From 02d30ab7993f45b8b0c5929d023271f61d210c60 Mon Sep 17 00:00:00 2001
From: Shaun Ruffell <sruffell@sruffell.net>
Date: Fri, 11 Jan 2019 03:59:45 +0000
Subject: [PATCH] Remove support for kernels older than 2.6.27

There are not any major distributions that are still supporting kernels
older than 2.6.27 so we can remove many typedefs. The primary motivator
for this change is that kernel 5.0 is dropping support for timeval and
it would be ideal if the in-kernel time representation can
standardize on ktime_t, but 2.6.18 did not support the ktime
interface that was needed.

Signed-off-by: Shaun Ruffell <sruffell@sruffell.net>
---
 drivers/dahdi/dahdi-base.c            |  46 ----------
 drivers/dahdi/dahdi-sysfs.c           |  67 --------------
 drivers/dahdi/dahdi-sysfs.h           |  15 ----
 drivers/dahdi/dahdi_dummy.c           |   3 +-
 drivers/dahdi/dahdi_dynamic_eth.c     |  19 +---
 drivers/dahdi/dahdi_dynamic_ethmf.c   |  20 +----
 drivers/dahdi/voicebus/GpakCust.c     |  14 ---
 drivers/dahdi/voicebus/GpakCust.h     |   3 -
 drivers/dahdi/voicebus/voicebus.c     |  31 +------
 drivers/dahdi/voicebus/voicebus.h     |   2 -
 drivers/dahdi/voicebus/voicebus_net.c |  38 +-------
 drivers/dahdi/voicebus/vpmoct.c       |  20 -----
 drivers/dahdi/wct4xxp/base.c          |  13 ---
 drivers/dahdi/wctc4xxp/base.c         |  79 +----------------
 drivers/dahdi/wctdm24xxp/base.c       |  26 ------
 drivers/dahdi/wctdm24xxp/wctdm24xxp.h |   4 -
 drivers/dahdi/wctdm24xxp/xhfc.c       |  10 ---
 drivers/dahdi/wcte13xp-base.c         |  10 ---
 drivers/dahdi/wcte43x-base.c          |  62 +------------
 drivers/dahdi/wcxb.c                  |  10 ---
 drivers/dahdi/wcxb.h                  |  11 ---
 drivers/dahdi/xpp/mmapdrv.c           |   3 -
 drivers/dahdi/xpp/xbus-core.c         |  10 ---
 drivers/dahdi/xpp/xbus-sysfs.c        |  30 -------
 drivers/dahdi/xpp/xdefs.h             |  23 +----
 drivers/dahdi/xpp/xpd.h               |   4 -
 drivers/dahdi/xpp/xpp_usb.c           |  30 ++-----
 include/dahdi/kernel.h                | 120 +-------------------------
 28 files changed, 15 insertions(+), 708 deletions(-)

diff --git a/drivers/dahdi/dahdi-base.c b/drivers/dahdi/dahdi-base.c
index 38df9c4..7892366 100644
--- a/drivers/dahdi/dahdi-base.c
+++ b/drivers/dahdi/dahdi-base.c
@@ -103,11 +103,7 @@
 #define chan_to_netdev(h) ((h)->hdlcnetdev->netdev)
 
 /* macro-oni for determining a unit (channel) number */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-#define	UNIT(file) MINOR(file->f_dentry->d_inode->i_rdev)
-#else
 #define	UNIT(file) MINOR(file->f_path.dentry->d_inode->i_rdev)
-#endif
 
 EXPORT_SYMBOL(dahdi_transcode_fops);
 EXPORT_SYMBOL(dahdi_init_tone_state);
@@ -1973,12 +1969,10 @@ static inline void print_debug_writebuf(struct dahdi_chan* ss, struct sk_buff *s
 #endif
 
 #ifdef CONFIG_DAHDI_NET
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 26)
 static inline struct net_device_stats *hdlc_stats(struct net_device *dev)
 {
 	return &dev->stats;
 }
-#endif
 
 static int dahdi_net_open(struct net_device *dev)
 {
@@ -3938,19 +3932,11 @@ static void __dahdi_find_master_span(void)
 		module_printk(KERN_NOTICE, "Master changed to %s\n", s->name);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void _dahdi_find_master_span(void *work)
-{
-	__dahdi_find_master_span();
-}
-static DECLARE_WORK(find_master_work, _dahdi_find_master_span, NULL);
-#else
 static void _dahdi_find_master_span(struct work_struct *work)
 {
 	__dahdi_find_master_span();
 }
 static DECLARE_WORK(find_master_work, _dahdi_find_master_span);
-#endif
 
 static void dahdi_find_master_span(void)
 {
@@ -4970,9 +4956,6 @@ static int dahdi_ioctl_chanconfig(struct file *file, unsigned long data)
 			chan->hdlcnetdev->netdev = alloc_hdlcdev(chan->hdlcnetdev);
 			if (chan->hdlcnetdev->netdev) {
 				chan->hdlcnetdev->chan = chan;
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 23)
-				SET_MODULE_OWNER(chan->hdlcnetdev->netdev);
-#endif
 				chan->hdlcnetdev->netdev->tx_queue_len = 50;
 #ifdef HAVE_NET_DEVICE_OPS
 				chan->hdlcnetdev->netdev->netdev_ops = &dahdi_netdev_ops;
@@ -9384,11 +9367,7 @@ that the waitqueue is empty. */
 #ifdef CONFIG_DAHDI_NET
 		if (skb && dahdi_have_netdev(ms))
 		{
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
-			skb->mac.raw = skb->data;
-#else
 			skb_reset_mac_header(skb);
-#endif
 			skb->dev = chan_to_netdev(ms);
 #ifdef DAHDI_HDLC_TYPE_TRANS
 			skb->protocol = hdlc_type_trans(skb,
@@ -10550,35 +10529,10 @@ failed_driver_init:
 	return res;
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 25)
-#ifdef CONFIG_PCI
-void dahdi_pci_disable_link_state(struct pci_dev *pdev, int state)
-{
-	u16 reg16;
-	int pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
-	state &= (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1 |
-		  PCIE_LINK_STATE_CLKPM);
-	if (!pos)
-		return;
-	pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
-	reg16 &= ~(state);
-	pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
-}
-EXPORT_SYMBOL(dahdi_pci_disable_link_state);
-#endif /* CONFIG_PCI */
-#endif /* 2.6.25 */
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 22)
-static inline void flush_find_master_work(void)
-{
-	flush_scheduled_work();
-}
-#else
 static inline void flush_find_master_work(void)
 {
 	cancel_work_sync(&find_master_work);
 }
-#endif
 
 static void __exit dahdi_cleanup(void)
 {
diff --git a/drivers/dahdi/dahdi-sysfs.c b/drivers/dahdi/dahdi-sysfs.c
index b440fab..d1f2379 100644
--- a/drivers/dahdi/dahdi-sysfs.c
+++ b/drivers/dahdi/dahdi-sysfs.c
@@ -61,38 +61,6 @@ static inline struct dahdi_span *dev_to_span(struct device *dev)
 		DAHDI_ADD_UEVENT_VAR("SPAN_NAME=%s", span->name);	\
 	} while (0)
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-#define DAHDI_ADD_UEVENT_VAR(fmt, val...)			\
-	do {							\
-		int err = add_uevent_var(envp, num_envp, &i,	\
-				buffer, buffer_size, &len,	\
-				fmt, val);			\
-		if (err)					\
-			return err;				\
-	} while (0)
-
-static int span_uevent(struct device *dev, char **envp, int num_envp,
-		char *buffer, int buffer_size)
-{
-	struct dahdi_span	*span;
-	int			i = 0;
-	int			len = 0;
-
-	if (!dev)
-		return -ENODEV;
-
-	span = dev_to_span(dev);
-	if (!span)
-		return -ENODEV;
-
-	dahdi_dbg(GENERAL, "SYFS dev_name=%s span=%s\n",
-			dev_name(dev), span->name);
-	SPAN_VAR_BLOCK;
-	envp[i] = NULL;
-	return 0;
-}
-
-#else
 #define DAHDI_ADD_UEVENT_VAR(fmt, val...)			\
 	do {							\
 		int err = add_uevent_var(kenv, fmt, val);	\
@@ -115,8 +83,6 @@ static int span_uevent(struct device *dev, struct kobj_uevent_env *kenv)
 	return 0;
 }
 
-#endif
-
 #define span_attr(field, format_string)				\
 static BUS_ATTR_READER(field##_show, dev, buf)			\
 {								\
@@ -465,37 +431,6 @@ static inline struct dahdi_device *to_ddev(struct device *dev)
 				ddev->location);			\
 	} while (0)
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-#define DAHDI_ADD_UEVENT_VAR(fmt, val...)			\
-	do {							\
-		int err = add_uevent_var(envp, num_envp, &i,	\
-				buffer, buffer_size, &len,	\
-				fmt, val);			\
-		if (err)					\
-			return err;				\
-	} while (0)
-
-static int device_uevent(struct device *dev, char **envp, int num_envp,
-		char *buffer, int buffer_size)
-{
-	struct dahdi_device	*ddev;
-	int			i = 0;
-	int			len = 0;
-
-	if (!dev)
-		return -ENODEV;
-
-	ddev = to_ddev(dev);
-	if (!ddev)
-		return -ENODEV;
-
-	dahdi_dbg(GENERAL, "SYFS dev_name=%s\n", dev_name(dev));
-	DEVICE_VAR_BLOCK;
-	envp[i] = NULL;
-	return 0;
-}
-
-#else
 #define DAHDI_ADD_UEVENT_VAR(fmt, val...)			\
 	do {							\
 		int err = add_uevent_var(kenv, fmt, val);	\
@@ -517,8 +452,6 @@ static int device_uevent(struct device *dev, struct kobj_uevent_env *kenv)
 	return 0;
 }
 
-#endif
-
 static ssize_t
 manufacturer_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
diff --git a/drivers/dahdi/dahdi-sysfs.h b/drivers/dahdi/dahdi-sysfs.h
index 9cbd9f9..a6f2479 100644
--- a/drivers/dahdi/dahdi-sysfs.h
+++ b/drivers/dahdi/dahdi-sysfs.h
@@ -22,27 +22,12 @@
 		ssize_t name(struct device_driver *drv, char * buf)
 
 /* Device file creation macros */
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
 #define CLASS_DEV_CREATE(class, devt, device, name) \
 	device_create(class, device, devt, NULL, "%s", name)
-#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
-#define CLASS_DEV_CREATE(class, devt, device, name) \
-	device_create(class, device, devt, name)
-#else
-#define CLASS_DEV_CREATE(class, devt, device, name) \
-	class_device_create(class, NULL, devt, device, name)
-#endif
 
 /* Device file destruction macros */
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
 #define CLASS_DEV_DESTROY(class, devt) \
 	device_destroy(class, devt)
-#else
-#define CLASS_DEV_DESTROY(class, devt) \
-	class_device_destroy(class, devt)
-#endif
 
 /* Global */
 int __init dahdi_sysfs_chan_init(const struct file_operations *fops);
diff --git a/drivers/dahdi/dahdi_dummy.c b/drivers/dahdi/dahdi_dummy.c
index b75c6a6..61e2c4f 100644
--- a/drivers/dahdi/dahdi_dummy.c
+++ b/drivers/dahdi/dahdi_dummy.c
@@ -38,8 +38,7 @@
 
 #include <linux/version.h>
 
-#if defined(CONFIG_HIGH_RES_TIMERS) && \
-	LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22)
+#if defined(CONFIG_HIGH_RES_TIMERS)
 #define USE_HIGHRESTIMER
 #endif
 
diff --git a/drivers/dahdi/dahdi_dynamic_eth.c b/drivers/dahdi/dahdi_dynamic_eth.c
index ab63d71..0209489 100644
--- a/drivers/dahdi/dahdi_dynamic_eth.c
+++ b/drivers/dahdi/dahdi_dynamic_eth.c
@@ -80,11 +80,7 @@ static int ztdeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet
 {
 	struct dahdi_span *span;
 	struct ztdeth_header *zh;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
 	zh = (struct ztdeth_header *)skb_network_header(skb);
-#else
-	zh = (struct ztdeth_header *)skb->nh.raw;
-#endif
 	span = ztdeth_getspan(eth_hdr(skb)->h_source, zh->subaddr);
 	if (span) {
 		skb_pull(skb, sizeof(struct ztdeth_header));
@@ -166,18 +162,9 @@ static void ztdeth_transmit(struct dahdi_dynamic *dyn, u8 *msg, size_t msglen)
 
 			/* Setup protocol and such */
 			skb->protocol = __constant_htons(ETH_P_DAHDI_DETH);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
 			skb_set_network_header(skb, 0);
-#else
-			skb->nh.raw = skb->data;
-#endif
 			skb->dev = dev;
-#if  LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
 			dev_hard_header(skb, dev, ETH_P_DAHDI_DETH, addr, dev->dev_addr, skb->len);
-#else
-			if (dev->hard_header)
-				dev->hard_header(skb, dev, ETH_P_DAHDI_DETH, addr, dev->dev_addr, skb->len);
-#endif
 			skb_queue_tail(&skbs, skb);
 		}
 	}
@@ -368,11 +355,7 @@ static int ztdeth_create(struct dahdi_dynamic *dyn, const char *addr)
 			}
 			z->subaddr = htons(sub);
 		}
-		z->dev = dev_get_by_name(
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
-				&init_net,
-#endif
-				z->ethdev);
+		z->dev = dev_get_by_name(&init_net, z->ethdev);
 		if (!z->dev) {
 			printk(KERN_NOTICE "TDMoE: Invalid device '%s'\n", z->ethdev);
 			kfree(z);
diff --git a/drivers/dahdi/dahdi_dynamic_ethmf.c b/drivers/dahdi/dahdi_dynamic_ethmf.c
index 90e4e6d..b729079 100644
--- a/drivers/dahdi/dahdi_dynamic_ethmf.c
+++ b/drivers/dahdi/dahdi_dynamic_ethmf.c
@@ -236,11 +236,7 @@ static int ztdethmf_rcv(struct sk_buff *skb, struct net_device *dev,
 	unsigned int samples, channels, rbslen, flags;
 	unsigned int skip = 0;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22)
 	zh = (struct ztdeth_header *) skb_network_header(skb);
-#else
-	zh = (struct ztdeth_header *) skb->nh.raw;
-#endif
 	if (ntohs(zh->subaddr) & 0x8000) {
 		/* got a multi-span frame */
 		num_spans = ntohs(zh->subaddr) & 0xFF;
@@ -484,19 +480,9 @@ static void ztdethmf_transmit(struct dahdi_dynamic *dyn, u8 *msg, size_t msglen)
 
 		/* Setup protocol type */
 		skb->protocol = __constant_htons(ETH_P_ZTDETH);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22)
 		skb_set_network_header(skb, 0);
-#else
-		skb->nh.raw = skb->data;
-#endif
 		skb->dev = dev;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
 		dev_hard_header(skb, dev, ETH_P_ZTDETH, addr, dev->dev_addr, skb->len);
-#else
-		if (dev->hard_header)
-			dev->hard_header(skb, dev, ETH_P_ZTDETH, addr,
-					dev->dev_addr, skb->len);
-#endif
 		/* queue frame for delivery */
 		if (dev) {
 			skb_queue_tail(&skbs, skb);
@@ -603,11 +589,7 @@ static int ztdethmf_create(struct dahdi_dynamic *dyn, const char *addr)
 		kfree(z);
 		return -EINVAL;
 	}
-	z->dev = dev_get_by_name(
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
-		&init_net,
-#endif
-		z->ethdev);
+	z->dev = dev_get_by_name(&init_net, z->ethdev);
 	if (!z->dev) {
 		printk(KERN_ERR "TDMoE Multiframe: Invalid device '%s'\n", z->ethdev);
 		kfree(z);
diff --git a/drivers/dahdi/voicebus/GpakCust.c b/drivers/dahdi/voicebus/GpakCust.c
index 31eefc3..61fd2bb 100644
--- a/drivers/dahdi/voicebus/GpakCust.c
+++ b/drivers/dahdi/voicebus/GpakCust.c
@@ -33,11 +33,7 @@
 #include <linux/version.h>
 #include <linux/types.h>
 #include <linux/pci.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
 #include <linux/semaphore.h>
-#else
-#include <asm/semaphore.h>
-#endif
 #include <linux/slab.h>
 
 #include <dahdi/kernel.h>
@@ -380,15 +376,9 @@ static void update_channel_config(struct vpmadt032 *vpm, unsigned int channel,
  * the hardware can take some time while messages are sent to the VPMADT032
  * module and the driver waits for the responses.
  */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void vpmadt032_bh(void *data)
-{
-	struct vpmadt032 *vpm = data;
-#else
 static void vpmadt032_bh(struct work_struct *data)
 {
 	struct vpmadt032 *vpm = container_of(data, struct vpmadt032, work);
-#endif
 	struct change_order *order;
 
 	while ((order = get_next_order(vpm))) {
@@ -514,11 +504,7 @@ vpmadt032_alloc(struct vpmadt032_options *options)
 	sema_init(&vpm->sem, 1);
 	vpm->curpage = 0x80;
 	vpm->dspid = -1;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&vpm->work, vpmadt032_bh, vpm);
-#else
 	INIT_WORK(&vpm->work, vpmadt032_bh);
-#endif
 
 	/* Do not use the global workqueue for processing these events.  Some of
 	 * the operations can take 100s of ms, most of that time spent sleeping.
diff --git a/drivers/dahdi/voicebus/GpakCust.h b/drivers/dahdi/voicebus/GpakCust.h
index fecb9e5..406f11d 100644
--- a/drivers/dahdi/voicebus/GpakCust.h
+++ b/drivers/dahdi/voicebus/GpakCust.h
@@ -42,10 +42,7 @@
 #include <linux/workqueue.h>
 #include <linux/delay.h>
 #include <linux/version.h>
-
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 25)
 #include <linux/semaphore.h>
-#endif
 
 #include "gpakenum.h"
 #include "adt_lec.h"
diff --git a/drivers/dahdi/voicebus/voicebus.c b/drivers/dahdi/voicebus/voicebus.c
index fb8c60c..8a1f7a6 100644
--- a/drivers/dahdi/voicebus/voicebus.c
+++ b/drivers/dahdi/voicebus/voicebus.c
@@ -1197,11 +1197,8 @@ voicebus_release(struct voicebus *vb)
 #endif
 
 	/* Make sure the underrun_work isn't running or going to run. */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 22)
-	flush_scheduled_work();
-#else
 	cancel_work_sync(&vb->underrun_work);
-#endif
+
 	/* quiesce the hardware */
 	voicebus_stop(vb);
 
@@ -1236,9 +1233,6 @@ vb_increase_latency(struct voicebus *vb, unsigned int increase,
 		    struct list_head *buffers)
 {
 	struct vbb *vbb;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 27)
-	struct vbb *n;
-#endif
 	int i;
 	LIST_HEAD(local);
 
@@ -1274,12 +1268,7 @@ vb_increase_latency(struct voicebus *vb, unsigned int increase,
 	}
 
 	handle_transmit(vb, &local);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 27)
-	list_for_each_entry_safe(vbb, n, &local, entry)
-		list_move_tail(&vbb->entry, buffers);
-#else
 	list_splice_tail(&local, buffers);
-#endif
 
 	/* Set the new latency (but we want to ensure that there aren't any
 	 * printks to the console, so we don't call the function) */
@@ -1633,16 +1622,10 @@ tx_error_exit:
  * @work: 	The work_struct used to queue this function.
  *
  */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void handle_hardunderrun(void *data)
-{
-	struct voicebus *vb = data;
-#else
 static void handle_hardunderrun(struct work_struct *work)
 {
 	struct voicebus *vb = container_of(work, struct voicebus,
 					   underrun_work);
-#endif
 	if (test_bit(VOICEBUS_STOP, &vb->flags) ||
 	    test_bit(VOICEBUS_STOPPED, &vb->flags))
 		return;
@@ -1677,11 +1660,7 @@ static void handle_hardunderrun(struct work_struct *work)
  * since it doesn't employ any locking on the voicebus interface.
  */
 static irqreturn_t
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-vb_isr(int irq, void *dev_id, struct pt_regs *regs)
-#else
 vb_isr(int irq, void *dev_id)
-#endif
 {
 	struct voicebus *vb = dev_id;
 	unsigned long flags;
@@ -1751,11 +1730,7 @@ vb_timer(TIMER_DATA_TYPE timer)
 {
 	unsigned long start = jiffies;
 	struct voicebus *vb = from_timer(vb, timer, timer);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	vb_isr(0, vb, 0);
-#else
 	vb_isr(0, vb);
-#endif
 	if (!test_bit(VOICEBUS_STOPPED, &vb->flags)) {
 		mod_timer(&vb->timer, start + HZ/1000);
 	}
@@ -1803,11 +1778,7 @@ __voicebus_init(struct voicebus *vb, const char *board_name,
 	timer_setup(&vb->timer, vb_timer, 0);
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&vb->underrun_work, handle_hardunderrun, vb);
-#else
 	INIT_WORK(&vb->underrun_work, handle_hardunderrun);
-#endif
 
 	/* ----------------------------------------------------------------
 	   Configure the hardware / kernel module interfaces.
diff --git a/drivers/dahdi/voicebus/voicebus.h b/drivers/dahdi/voicebus/voicebus.h
index 9518028..faece9a 100644
--- a/drivers/dahdi/voicebus/voicebus.h
+++ b/drivers/dahdi/voicebus/voicebus.h
@@ -173,9 +173,7 @@ struct voicebus {
 	struct sk_buff_head captured_packets;
 	struct net_device *netdev;
 	struct net_device_stats net_stats;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
 	struct napi_struct napi;
-#endif
 	atomic_t tx_seqnum;
 	atomic_t rx_seqnum;
 #endif
diff --git a/drivers/dahdi/voicebus/voicebus_net.c b/drivers/dahdi/voicebus/voicebus_net.c
index 27475a5..c17627c 100644
--- a/drivers/dahdi/voicebus/voicebus_net.c
+++ b/drivers/dahdi/voicebus/voicebus_net.c
@@ -104,26 +104,6 @@ static int vb_net_receive(struct voicebus *vb, int max)
 	return count;
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-static int vb_net_poll(struct net_device *netdev, int *budget)
-{
-	struct voicebus *vb = voicebus_from_netdev(netdev);
-	int count = 0;
-	int quota = min(netdev->quota, *budget);
-
-	count = vb_net_receive(vb, quota);
-
-	*budget -=       count;
-	netdev->quota -= count;
-
-	if (!skb_queue_len(&vb->captured_packets)) {
-		netif_rx_complete(netdev);
-		return 0;
-	} else {
-		return -1;
-	}
-}
-#else
 static int vb_net_poll(struct napi_struct *napi, int budget)
 {
 	struct voicebus *vb = container_of(napi, struct voicebus, napi);
@@ -142,7 +122,6 @@ static int vb_net_poll(struct napi_struct *napi, int budget)
 	}
 	return count;
 }
-#endif
 
 static void vb_net_set_multi(struct net_device *netdev)
 {
@@ -155,11 +134,7 @@ static int vb_net_up(struct net_device *netdev)
 {
 	struct voicebus *vb = voicebus_from_netdev(netdev);
 	dev_dbg(&vb->pdev->dev, "%s\n", __func__);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netif_poll_enable(netdev);
-#else
 	napi_enable(&vb->napi);
-#endif
 	return 0;
 }
 
@@ -167,11 +142,7 @@ static int vb_net_down(struct net_device *netdev)
 {
 	struct voicebus *vb = voicebus_from_netdev(netdev);
 	dev_dbg(&vb->pdev->dev, "%s\n", __func__);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netif_poll_disable(netdev);
-#else
 	napi_disable(&vb->napi);
-#endif
 	return 0;
 }
 
@@ -231,12 +202,7 @@ int vb_net_register(struct voicebus *vb, const char *board_name)
 
 	netdev->promiscuity = 0;
 	netdev->flags |= IFF_NOARP;
-#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netdev->poll = vb_net_poll;
-	netdev->weight = 64;
-#	else
 	netif_napi_add(netdev, &vb->napi, vb_net_poll, 64);
-#	endif
 
 	skb_queue_head_init(&vb->captured_packets);
 	res = register_netdev(netdev);
@@ -359,9 +325,7 @@ void vb_net_capture_vbb(struct voicebus *vb, const void *vbb, const int tx,
 		return;
 
 	skb_queue_tail(&vb->captured_packets, skb);
-#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netif_rx_schedule(netdev);
-#	elif LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
+#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
 	netif_rx_schedule(netdev, &vb->napi);
 #	elif LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 30)
 	netif_rx_schedule(&vb->napi);
diff --git a/drivers/dahdi/voicebus/vpmoct.c b/drivers/dahdi/voicebus/vpmoct.c
index 67fc911..801fa86 100644
--- a/drivers/dahdi/voicebus/vpmoct.c
+++ b/drivers/dahdi/voicebus/vpmoct.c
@@ -393,16 +393,10 @@ struct vpmoct_load_work {
  * long running firmware load.
  *
  */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void vpmoct_load_complete_fn(void *data)
-{
-	struct vpmoct_load_work *work = data;
-#else
 static void vpmoct_load_complete_fn(struct work_struct *data)
 {
 	struct vpmoct_load_work *work =
 			container_of(data, struct vpmoct_load_work, work);
-#endif
 	/* Do not touch work->vpm after calling load complete. It may have
 	 * been freed in the function by the board driver. */
 	work->load_complete(work->vpm->dev, work->operational);
@@ -421,11 +415,7 @@ vpmoct_load_complete(struct vpmoct_load_work *work, bool operational)
 {
 	work->operational = operational;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&work->work, vpmoct_load_complete_fn, work);
-#else
 	INIT_WORK(&work->work, vpmoct_load_complete_fn);
-#endif
 	schedule_work(&work->work);
 }
 
@@ -490,16 +480,10 @@ static void vpmoct_release_firmware(const struct firmware *fw)
  * @vpm:  The VPMOCT032 module to check / load.
  *
  */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void vpmoct_load_flash(void *data)
-{
-	struct vpmoct_load_work *work = data;
-#else
 static void vpmoct_load_flash(struct work_struct *data)
 {
 	struct vpmoct_load_work *work =
 			container_of(data, struct vpmoct_load_work, work);
-#endif
 	int res;
 	struct vpmoct *const vpm = work->vpm;
 	const struct firmware *fw;
@@ -686,11 +670,7 @@ int vpmoct_init(struct vpmoct *vpm, load_complete_func_t load_complete)
 		return -ENOMEM;
 	}
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&work->work, vpmoct_load_flash, work);
-#else
 	INIT_WORK(&work->work, vpmoct_load_flash);
-#endif
 
 	work->vpm = vpm;
 	work->load_complete = load_complete;
diff --git a/drivers/dahdi/wct4xxp/base.c b/drivers/dahdi/wct4xxp/base.c
index 6b9072e..1b37c43 100644
--- a/drivers/dahdi/wct4xxp/base.c
+++ b/drivers/dahdi/wct4xxp/base.c
@@ -48,15 +48,12 @@
 #include "wct4xxp.h"
 #include "vpm450m.h"
 
-/* Work queues are a way to better distribute load on SMP systems */
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
 /*
  * Work queues can significantly improve performance and scalability
  * on multi-processor machines, but requires bypassing some kernel
  * API's, so it's not guaranteed to be compatible with all kernels.
  */
 /* #define ENABLE_WORKQUEUES */
-#endif
 
 /* Support first generation cards? */
 #define SUPPORT_GEN1 
@@ -4048,15 +4045,9 @@ static void t4_increase_latency(struct t4 *wc, int newlatency)
 
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void t4_work_func(void *data)
-{
-	struct t4 *wc = data;
-#else
 static void t4_work_func(struct work_struct *work)
 {
 	struct t4 *wc = container_of(work, struct t4, bh_work);
-#endif
 
 	if (test_bit(T4_CHANGE_LATENCY, &wc->checkflag)) {
 		if (wc->needed_latency != wc->numbufs) {
@@ -5144,11 +5135,7 @@ static int __devinit t4_launch(struct t4 *wc)
 			      &wc->ddev->spans);
 	}
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&wc->bh_work, t4_work_func, wc);
-#else
 	INIT_WORK(&wc->bh_work, t4_work_func);
-#endif
 
 	res = dahdi_register_device(wc->ddev, &wc->dev->dev);
 	if (res) {
diff --git a/drivers/dahdi/wctc4xxp/base.c b/drivers/dahdi/wctc4xxp/base.c
index 88d3865..55c6026 100644
--- a/drivers/dahdi/wctc4xxp/base.c
+++ b/drivers/dahdi/wctc4xxp/base.c
@@ -239,13 +239,8 @@ initialize_cmd(struct tcb *cmd, unsigned long cmd_flags)
 	cmd->flags = cmd_flags;
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-/*! Used to allocate commands to submit to the dte. */
-kmem_cache_t *cmd_cache;
-#else
 /*! Used to allocate commands to submit to the dte. */
 static struct kmem_cache *cmd_cache;
-#endif
 
 static inline struct tcb *
 __alloc_cmd(size_t size, gfp_t alloc_flags, unsigned long cmd_flags)
@@ -376,9 +371,7 @@ struct wcdte {
 	struct sk_buff_head captured_packets;
 	struct net_device *netdev;
 	struct net_device_stats net_stats;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
 	struct napi_struct napi;
-#endif
 	struct timer_list watchdog;
 	u16 open_channels;
 	unsigned long reported_packet_errors;
@@ -501,11 +494,7 @@ wctc4xxp_net_up(struct net_device *netdev)
 {
 	struct wcdte *wc = wcdte_from_netdev(netdev);
 	DTE_DEBUG(DTE_DEBUG_GENERAL, "%s\n", __func__);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netif_poll_enable(netdev);
-#else
 	napi_enable(&wc->napi);
-#endif
 	return 0;
 }
 
@@ -514,11 +503,7 @@ wctc4xxp_net_down(struct net_device *netdev)
 {
 	struct wcdte *wc = wcdte_from_netdev(netdev);
 	DTE_DEBUG(DTE_DEBUG_GENERAL, "%s\n", __func__);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netif_poll_disable(netdev);
-#else
 	napi_disable(&wc->napi);
-#endif
 	return 0;
 }
 
@@ -558,27 +543,6 @@ wctc4xxp_net_receive(struct wcdte *wc, int max)
 	return count;
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-static int
-wctc4xxp_poll(struct net_device *netdev, int *budget)
-{
-	struct wcdte *wc = wcdte_from_netdev(netdev);
-	int count = 0;
-	int quota = min(netdev->quota, *budget);
-
-	count = wctc4xxp_net_receive(wc, quota);
-
-	*budget -=       count;
-	netdev->quota -= count;
-
-	if (!skb_queue_len(&wc->captured_packets)) {
-		netif_rx_complete(netdev);
-		return 0;
-	} else {
-		return -1;
-	}
-}
-#else
 static int
 wctc4xxp_poll(struct napi_struct *napi, int budget)
 {
@@ -598,7 +562,6 @@ wctc4xxp_poll(struct napi_struct *napi, int budget)
 	}
 	return count;
 }
-#endif
 
 static struct net_device_stats *
 wctc4xxp_net_get_stats(struct net_device *netdev)
@@ -690,12 +653,7 @@ wctc4xxp_net_register(struct wcdte *wc)
 	netdev->promiscuity = 0;
 	netdev->flags |= IFF_NOARP;
 
-#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netdev->poll = &wctc4xxp_poll;
-	netdev->weight = 64;
-#	else
 	netif_napi_add(netdev, &wc->napi, &wctc4xxp_poll, 64);
-#	endif
 
 	res = register_netdev(netdev);
 	if (res) {
@@ -765,9 +723,7 @@ wctc4xxp_net_capture_cmd(struct wcdte *wc, const struct tcb *cmd)
 		return;
 
 	skb_queue_tail(&wc->captured_packets, skb);
-#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	netif_rx_schedule(netdev);
-#	elif LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
+#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
 	netif_rx_schedule(netdev, &wc->napi);
 #	elif LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 30)
 	netif_rx_schedule(&wc->napi);
@@ -1977,13 +1933,9 @@ wctc4xxp_operation_allocate(struct dahdi_transcoder_channel *dtc)
 	int res = 0;
 	struct wcdte *wc = ((struct channel_pvt *)(dtc->pvt))->wc;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	mutex_lock(&wc->chanlock);
-#else
 	res = mutex_lock_killable(&wc->chanlock);
 	if (res)
 		return res;
-#endif
 
 	++wc->open_channels;
 
@@ -2056,13 +2008,9 @@ wctc4xxp_operation_release(struct dahdi_transcoder_channel *dtc)
 	BUG_ON(!cpvt);
 	BUG_ON(!wc);
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	mutex_lock(&wc->chanlock);
-#else
 	res = mutex_lock_killable(&wc->chanlock);
 	if (res)
 		return res;
-#endif
 
 	if (test_bit(DTE_SHUTDOWN, &wc->flags)) {
 		/* On shutdown, if we reload the firmware we will reset the
@@ -2777,15 +2725,9 @@ static void service_rx_ring(struct wcdte *wc)
 	wctc4xxp_receive_demand_poll(wc);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void deferred_work_func(void *param)
-{
-	struct wcdte *wc = param;
-#else
 static void deferred_work_func(struct work_struct *work)
 {
 	struct wcdte *wc = container_of(work, struct wcdte, deferred_work);
-#endif
 	service_rx_ring(wc);
 }
 
@@ -3902,16 +3844,11 @@ static ssize_t wctc4xxp_force_alert_store(struct device *dev,
 	}
 
 	dev_info(&wc->pdev->dev, "Forcing alert type: 0x%x\n", alert_type);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-	mutex_lock(&wc->chanlock);
-#else
 	res = mutex_lock_killable(&wc->chanlock);
 	if (res) {
 		free_cmd(cmd);
 		return -EAGAIN;
 	}
-#endif
-
 
 	parameters[0] = alert_type;
 
@@ -4000,11 +3937,7 @@ wctc4xxp_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	INIT_LIST_HEAD(&wc->cmd_list);
 	INIT_LIST_HEAD(&wc->waiting_for_response_list);
 	INIT_LIST_HEAD(&wc->rx_list);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&wc->deferred_work, deferred_work_func, wc);
-#else
 	INIT_WORK(&wc->deferred_work, deferred_work_func);
-#endif
 	init_waitqueue_head(&wc->waitq);
 
 	if (pci_set_dma_mask(wc->pdev, DMA_BIT_MASK(32))) {
@@ -4295,20 +4228,10 @@ static int __init wctc4xxp_init(void)
 	int res;
 	unsigned long cache_flags;
 
-#if defined(CONFIG_SLUB) && (LINUX_VERSION_CODE == KERNEL_VERSION(2, 6, 22))
-	cache_flags = SLAB_HWCACHE_ALIGN | SLAB_STORE_USER | SLAB_DEBUG_FREE;
-#else
 	cache_flags = SLAB_HWCACHE_ALIGN;
-#endif
 
-#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 23)
-	cmd_cache = kmem_cache_create(THIS_MODULE->name, sizeof(struct tcb),
-			0, cache_flags, NULL, NULL);
-#	else
 	cmd_cache = kmem_cache_create(THIS_MODULE->name, sizeof(struct tcb),
 			0, cache_flags, NULL);
-#	endif
-
 	if (!cmd_cache)
 		return -ENOMEM;
 	spin_lock_init(&wctc4xxp_list_lock);
diff --git a/drivers/dahdi/wctdm24xxp/base.c b/drivers/dahdi/wctdm24xxp/base.c
index 95ff5bc..d2e481a 100644
--- a/drivers/dahdi/wctdm24xxp/base.c
+++ b/drivers/dahdi/wctdm24xxp/base.c
@@ -50,11 +50,7 @@ Tx Gain - W/Pre-Emphasis: -23.99 to 0.00 db
 #include <linux/delay.h>
 #include <linux/moduleparam.h>
 #include <linux/firmware.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
 #include <linux/semaphore.h>
-#else
-#include <asm/semaphore.h>
-#endif
 #include <linux/crc32.h>
 #include <linux/slab.h>
 
@@ -332,15 +328,9 @@ struct bg {
 	int			ret;
 };
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void bg_work_func(void *data)
-{
-	struct bg *bg = data;
-#else
 static void bg_work_func(struct work_struct *work)
 {
 	struct bg *bg = container_of(work, struct bg, work);
-#endif
 	bg->ret = bg->fn(bg->wc, bg->param);
 	complete(&bg->complete);
 }
@@ -377,11 +367,7 @@ bg_create(struct wctdm *wc, bg_work_func_t fn, unsigned long param)
 	}
 
 	init_completion(&bg->complete);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&bg->work, bg_work_func, bg);
-#else
 	INIT_WORK(&bg->work, bg_work_func);
-#endif
 
 	bg->wc = wc;
 	bg->fn = fn;
@@ -463,16 +449,10 @@ struct vpmadt032_channel_setup {
 	struct wctdm		*wc;
 };
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void vpm_setup_work_func(void *data)
-{
-	struct vpmadt032_channel_setup *setup = data;
-#else
 static void vpm_setup_work_func(struct work_struct *work)
 {
 	struct vpmadt032_channel_setup *setup =
 		container_of(work, struct vpmadt032_channel_setup, work);
-#endif
 	int i;
 	int res;
 	GpakChannelConfig_t chanconfig;
@@ -634,13 +614,7 @@ static int config_vpmadt032(struct vpmadt032 *vpm, struct wctdm *wc)
 		return -ENOMEM;
 
 	setup->wc = wc;
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&setup->work, vpm_setup_work_func, setup);
-#else
 	INIT_WORK(&setup->work, vpm_setup_work_func);
-#endif
-
 	queue_work(vpm->wq, &setup->work);
 
 	return 0;
diff --git a/drivers/dahdi/wctdm24xxp/wctdm24xxp.h b/drivers/dahdi/wctdm24xxp/wctdm24xxp.h
index af30662..389690c 100644
--- a/drivers/dahdi/wctdm24xxp/wctdm24xxp.h
+++ b/drivers/dahdi/wctdm24xxp/wctdm24xxp.h
@@ -29,11 +29,7 @@
 #include <dahdi/kernel.h>
 
 #include <linux/version.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
 #include <linux/semaphore.h>
-#else
-#include <asm/semaphore.h>
-#endif
 
 #include "voicebus/voicebus.h"
 
diff --git a/drivers/dahdi/wctdm24xxp/xhfc.c b/drivers/dahdi/wctdm24xxp/xhfc.c
index e283e6f..d37fbd5 100644
--- a/drivers/dahdi/wctdm24xxp/xhfc.c
+++ b/drivers/dahdi/wctdm24xxp/xhfc.c
@@ -2386,15 +2386,9 @@ int b400m_dchan(struct dahdi_span *span)
 
 /*
  */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void xhfc_work(void *data)
-{
-	struct b400m *b4 = data;
-#else
 static void xhfc_work(struct work_struct *work)
 {
 	struct b400m *b4 = container_of(work, struct b400m, xhfc_wq);
-#endif
 	int i, j, k, fifo;
 	unsigned char b, b2;
 
@@ -2630,11 +2624,7 @@ void b400m_post_init(struct b400m *b4)
 	snprintf(b4->name, sizeof(b4->name) - 1, "b400m-%d",
 		 b4->b400m_no);
 	b4->xhfc_ws = create_singlethread_workqueue(b4->name);
-#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&b4->xhfc_wq, xhfc_work, b4);
-#	else
 	INIT_WORK(&b4->xhfc_wq, xhfc_work);
-#	endif
 	b4->inited = 1;
 }
 
diff --git a/drivers/dahdi/wcte13xp-base.c b/drivers/dahdi/wcte13xp-base.c
index ef9b5cd..25d4e31 100644
--- a/drivers/dahdi/wcte13xp-base.c
+++ b/drivers/dahdi/wcte13xp-base.c
@@ -2272,15 +2272,9 @@ static void te13x_handle_transmit(struct wcxb *xb, void *vfp)
 #define SPAN_ALARMS \
 	(wc->span.alarms & ~DAHDI_ALARM_NOTOPEN)
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void timer_work_func(void *param)
-{
-	struct t13x *wc = param;
-#else
 static void timer_work_func(struct work_struct *work)
 {
 	struct t13x *wc = container_of(work, struct t13x, timer_work);
-#endif
 	static int work_count;
 
 	if (debug)
@@ -2585,11 +2579,7 @@ static int __devinit te13xp_init_one(struct pci_dev *pdev,
 	mutex_init(&wc->lock);
 	timer_setup(&wc->timer, te13xp_timer, 0);
 
-#	if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&wc->timer_work, timer_work_func, wc);
-#	else
 	INIT_WORK(&wc->timer_work, timer_work_func);
-#	endif
 
 	wc->ddev = dahdi_create_device();
 	if (!wc->ddev) {
diff --git a/drivers/dahdi/wcte43x-base.c b/drivers/dahdi/wcte43x-base.c
index 74018ea..722d18d 100644
--- a/drivers/dahdi/wcte43x-base.c
+++ b/drivers/dahdi/wcte43x-base.c
@@ -55,19 +55,6 @@
 #include "wcxb_spi.h"
 #include "wcxb_flash.h"
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-#  ifdef RHEL_RELEASE_VERSION
-#    if RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(5, 6)
-#      define T43X_HAVE_CANCEL_WORK_SYNC
-#    endif
-#  else
-static inline int delayed_work_pending(struct work_struct *work)
-{
-	return test_bit(0, &work->pending);
-}
-#  endif
-#endif
-
 static const char *TE435_FW_FILENAME = "dahdi-fw-te435.bin";
 static const char *TE436_FW_FILENAME = "dahdi-fw-te436.bin";
 static const u32 TE435_VERSION = 0x13001e;
@@ -120,11 +107,7 @@ struct t43x_span {
 };
 
 struct t43x_clksrc_work {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	struct work_struct work;
-#else
 	struct delayed_work work;
-#endif
 	spinlock_t lock;
 	enum wcxb_clock_sources clksrc;
 	bool is_timing_master;
@@ -1191,16 +1174,10 @@ static void __t43x_set_rclk_src(struct t43x *wc, int span)
 
 /* This is called from the workqueue to wait for the TDM engine stop */
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void t43x_clksrc_work_fn(void *data)
-{
-	struct t43x_clksrc_work  *work = data;
-#else
 static void t43x_clksrc_work_fn(struct work_struct *data)
 {
-	struct t43x_clksrc_work  *work = container_of(to_delayed_work(data),
-						struct t43x_clksrc_work, work);
-#endif
+	struct t43x_clksrc_work *work = container_of(data,
+					  struct t43x_clksrc_work, work.work);
 	struct t43x *wc = container_of(work, struct t43x, clksrc_work);
 
 	if (debug) {
@@ -2029,16 +2006,10 @@ struct maint_work_struct {
 	struct dahdi_span *span;
 };
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void t43x_maint_work(void *data)
-{
-	struct maint_work_struct *w = data;
-#else
 static void t43x_maint_work(struct work_struct *work)
 {
 	struct maint_work_struct *w = container_of(work,
 					struct maint_work_struct, work);
-#endif
 
 	struct t43x *wc = w->wc;
 	struct dahdi_span *span = w->span;
@@ -2289,11 +2260,7 @@ static int t43x_maint(struct dahdi_span *span, int cmd)
 	work->wc = wc;
 	work->cmd = cmd;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&work->work, t43x_maint_work, work);
-#else
 	INIT_WORK(&work->work, t43x_maint_work);
-#endif
 	queue_work(wc->wq, &work->work);
 	return 0;
 }
@@ -3075,15 +3042,9 @@ static void t43x_handle_transmit(struct wcxb *xb, void *vfp)
 #define SPAN_ALARMS \
 	(ts->span.alarms & ~DAHDI_ALARM_NOTOPEN)
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-static void timer_work_func(void *param)
-{
-	struct t43x *wc = param;
-#else
 static void timer_work_func(struct work_struct *work)
 {
 	struct t43x *wc = container_of(work, struct t43x, timer_work);
-#endif
 	struct t43x_span *ts;
 	int x;
 	bool start_timer = false;
@@ -3434,18 +3395,8 @@ static int __devinit t43x_init_one(struct pci_dev *pdev,
 	mutex_init(&wc->lock);
 	timer_setup(&wc->timer, t43x_timer, 0);
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&wc->timer_work, timer_work_func, wc);
-#else
 	INIT_WORK(&wc->timer_work, timer_work_func);
-#endif
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-	INIT_WORK(&wc->clksrc_work.work, t43x_clksrc_work_fn,
-		  &wc->clksrc_work.work);
-#else
 	INIT_DELAYED_WORK(&wc->clksrc_work.work, t43x_clksrc_work_fn);
-#endif
 	spin_lock_init(&wc->clksrc_work.lock);
 
 	wc->ddev = dahdi_create_device();
@@ -3601,16 +3552,7 @@ static void __devexit t43x_remove_one(struct pci_dev *pdev)
 		release_vpm450m(wc->vpm);
 	wc->vpm = NULL;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-#  ifdef T43X_HAVE_CANCEL_WORK_SYNC 
-	cancel_work_sync(&wc->clksrc_work.work);
-#  else
-	cancel_delayed_work(&wc->clksrc_work.work);
-	flush_workqueue(wc->wq);
-#  endif
-#else
 	cancel_delayed_work_sync(&wc->clksrc_work.work);
-#endif
 
 	del_timer_sync(&wc->timer);
 	flush_workqueue(wc->wq);
diff --git a/drivers/dahdi/wcxb.c b/drivers/dahdi/wcxb.c
index 7068fae..4eaba8f 100644
--- a/drivers/dahdi/wcxb.c
+++ b/drivers/dahdi/wcxb.c
@@ -31,10 +31,8 @@
 #include <linux/version.h>
 #include <linux/slab.h>
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 26)
 #define HAVE_RATELIMIT
 #include <linux/ratelimit.h>
-#endif
 
 #include <dahdi/kernel.h>
 
@@ -129,11 +127,7 @@ static inline bool wcxb_is_pcie(const struct wcxb *xb)
 #if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 33)
 	return pci_is_pcie(xb->pdev);
 #else
-#ifndef WCXB_PCI_DEV_DOES_NOT_HAVE_IS_PCIE
 	return (xb->pdev->is_pcie > 0);
-#else
-	return (xb->flags.is_pcie > 0);
-#endif
 #endif
 }
 
@@ -653,10 +647,6 @@ int wcxb_init(struct wcxb *xb, const char *board_name, u32 int_mode)
 
 	pci_set_master(pdev);
 
-#ifdef WCXB_PCI_DEV_DOES_NOT_HAVE_IS_PCIE
-	xb->flags.is_pcie = pci_find_capability(pdev, PCI_CAP_ID_EXP) ? 1 : 0;
-#endif
-
 	WARN_ON(!pdev);
 	if (!pdev)
 		return -EINVAL;
diff --git a/drivers/dahdi/wcxb.h b/drivers/dahdi/wcxb.h
index d23c89f..7dbf2ab 100644
--- a/drivers/dahdi/wcxb.h
+++ b/drivers/dahdi/wcxb.h
@@ -27,14 +27,6 @@
 #define WCXB_DEFAULT_MAXLATENCY 12U
 #define WCXB_DMA_CHAN_SIZE	128
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-/* The is_pcie member was backported but I'm not sure in which version. */
-#  ifndef RHEL_RELEASE_VERSION
-#define WCXB_PCI_DEV_DOES_NOT_HAVE_IS_PCIE
-#  endif
-#else
-#endif
-
 struct wcxb;
 
 struct wcxb_operations {
@@ -63,9 +55,6 @@ struct wcxb {
 		u32	have_msi:1;
 		u32	latency_locked:1;
 		u32	drive_timing_cable:1;
-#ifdef WCXB_PCI_DEV_DOES_NOT_HAVE_IS_PCIE
-		u32	is_pcie:1;
-#endif
 		u32	dma_ins:1;
 	} flags;
 	void __iomem			*membase;
diff --git a/drivers/dahdi/xpp/mmapdrv.c b/drivers/dahdi/xpp/mmapdrv.c
index f0d6548..2e0e298 100644
--- a/drivers/dahdi/xpp/mmapdrv.c
+++ b/drivers/dahdi/xpp/mmapdrv.c
@@ -561,9 +561,6 @@ static int __init xpp_mmap_init(void)
 	xframe_cache =
 	    kmem_cache_create("xframe_cache",
 			      sizeof(xframe_t) + XFRAME_DATASIZE, 0, 0,
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 23)
-			      NULL,
-#endif
 			      NULL);
 	if (!xframe_cache) {
 		ret = -ENOMEM;
diff --git a/drivers/dahdi/xpp/xbus-core.c b/drivers/dahdi/xpp/xbus-core.c
index 565d267..9a6c3b3 100644
--- a/drivers/dahdi/xpp/xbus-core.c
+++ b/drivers/dahdi/xpp/xbus-core.c
@@ -1152,16 +1152,10 @@ err:
  * it returns only when all XPD's on the bus are detected and
  * initialized.
  */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
 static void xbus_populate(struct work_struct *work)
 {
 	struct xbus_workqueue *worker =
 	    container_of(work, struct xbus_workqueue, xpds_init_work);
-#else
-void xbus_populate(void *data)
-{
-	struct xbus_workqueue *worker = data;
-#endif
 	xbus_t *xbus;
 	struct list_head *card;
 	struct list_head *next_card;
@@ -1238,11 +1232,7 @@ int xbus_process_worker(xbus_t *xbus)
 	}
 	XBUS_DBG(DEVICES, xbus, "\n");
 	/* Initialize the work. (adapt to kernel API changes). */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
 	INIT_WORK(&worker->xpds_init_work, xbus_populate);
-#else
-	INIT_WORK(&worker->xpds_init_work, xbus_populate, worker);
-#endif
 	BUG_ON(!xbus);
 	/* Now send it */
 	if (!queue_work(worker->wq, &worker->xpds_init_work)) {
diff --git a/drivers/dahdi/xpp/xbus-sysfs.c b/drivers/dahdi/xpp/xbus-sysfs.c
index a3c8ae2..8c4859e 100644
--- a/drivers/dahdi/xpp/xbus-sysfs.c
+++ b/drivers/dahdi/xpp/xbus-sysfs.c
@@ -407,34 +407,6 @@ static int astribank_match(struct device *dev, struct device_driver *driver)
 		XBUS_ADD_UEVENT_VAR("XBUS_NAME=%s", xbus->busname);	\
 	} while (0)
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
-#define XBUS_ADD_UEVENT_VAR(fmt, val...)			\
-	do {							\
-		int err = add_uevent_var(envp, num_envp, &i,	\
-				buffer, buffer_size, &len,	\
-				fmt, val);			\
-		if (err)					\
-			return err;				\
-	} while (0)
-
-static int astribank_uevent(struct device *dev, char **envp, int num_envp,
-			    char *buffer, int buffer_size)
-{
-	xbus_t *xbus;
-	int i = 0;
-	int len = 0;
-	extern char *initdir;
-
-	if (!dev)
-		return -ENODEV;
-	xbus = dev_to_xbus(dev);
-	DBG(GENERAL, "SYFS bus_id=%s xbus=%s\n", dev_name(dev), xbus->busname);
-	XBUS_VAR_BLOCK;
-	envp[i] = NULL;
-	return 0;
-}
-
-#else
 #define XBUS_ADD_UEVENT_VAR(fmt, val...)			\
 	do {							\
 		int err = add_uevent_var(kenv, fmt, val);	\
@@ -455,8 +427,6 @@ static int astribank_uevent(struct device *dev, struct kobj_uevent_env *kenv)
 	return 0;
 }
 
-#endif
-
 void astribank_uevent_send(xbus_t *xbus, enum kobject_action act)
 {
 	struct kobject *kobj;
diff --git a/drivers/dahdi/xpp/xdefs.h b/drivers/dahdi/xpp/xdefs.h
index 61e071a..7da406f 100644
--- a/drivers/dahdi/xpp/xdefs.h
+++ b/drivers/dahdi/xpp/xdefs.h
@@ -103,11 +103,7 @@ typedef char *charp;
 #ifdef __KERNEL__
 
 /* Kernel versions... */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
-#define	KMEM_CACHE_T	kmem_cache_t
-#else
 #define	KMEM_CACHE_T	struct kmem_cache
-#endif
 
 #define	KZALLOC(size, gfp)	my_kzalloc(size, gfp)
 #define	KZFREE(p) \
@@ -116,7 +112,6 @@ typedef char *charp;
 			kfree(p);			\
 		} while (0);
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 14)
 #define	DEVICE_ATTR_READER(name, dev, buf) \
 		ssize_t name(struct device *dev, \
 		struct device_attribute *attr, char *buf)
@@ -124,12 +119,6 @@ typedef char *charp;
 		ssize_t name(struct device *dev, \
 		struct device_attribute *attr, \
 		const char *buf, size_t count)
-#else
-#define	DEVICE_ATTR_READER(name, dev, buf) \
-		ssize_t name(struct device *dev, char *buf)
-#define	DEVICE_ATTR_WRITER(name, dev, buf, count) \
-		ssize_t name(struct device *dev, const char *buf, size_t count)
-#endif
 #define	DRIVER_ATTR_READER(name, drv, buf) \
 		ssize_t name(struct device_driver *drv, char * buf)
 
@@ -142,19 +131,9 @@ typedef char *charp;
 #define	SET_PROC_DIRENTRY_OWNER(p) do { } while (0);
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
-/* Also don't define this for later RHEL >= 5.2. */
-#if defined(RHEL_RELEASE_CODE) && defined(RHEL_RELEASE_VERSION)
-#if RHEL_RELEASE_CODE < RHEL_RELEASE_VERSION(5, 3)
-typedef int bool;
-#endif
 #else
 typedef int bool;
-#endif
-#endif
-#else
-typedef int bool;
-#endif
+#endif /* ifdef __KERNEL__ */
 typedef struct xbus xbus_t;
 typedef struct xpd xpd_t;
 typedef struct xframe xframe_t;
diff --git a/drivers/dahdi/xpp/xpd.h b/drivers/dahdi/xpp/xpd.h
index 372aa33..c59ed36 100644
--- a/drivers/dahdi/xpp/xpd.h
+++ b/drivers/dahdi/xpp/xpd.h
@@ -32,11 +32,7 @@
 #include <linux/version.h>
 #include <asm/atomic.h>
 #include <linux/slab.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
 #include <linux/semaphore.h>
-#else
-#include <asm/semaphore.h>
-#endif
 #include <linux/moduleparam.h>
 #endif /* __KERNEL__ */
 
diff --git a/drivers/dahdi/xpp/xpp_usb.c b/drivers/dahdi/xpp/xpp_usb.c
index fa48157..a599e6f 100644
--- a/drivers/dahdi/xpp/xpp_usb.c
+++ b/drivers/dahdi/xpp/xpp_usb.c
@@ -222,20 +222,8 @@ static unsigned bus_count;
 /* prevent races between open() and disconnect() */
 static DEFINE_MUTEX(protect_xusb_devices);
 
-/*
- * AsteriskNow kernel has backported the "lean" callback from 2.6.20
- * to 2.6.19 without any macro to notify of this fact -- how lovely.
- * Debian-Etch and Centos5 are using 2.6.18 for now (lucky for us).
- * Fedora6 jumped from 2.6.18 to 2.6.20. So far luck is on our side ;-)
- */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
-#define	USB_PASS_CB(u)	struct urb *u, struct pt_regs *regs
-#else
-#define	USB_PASS_CB(u)	struct urb *u
-#endif
-
-static void xpp_send_callback(USB_PASS_CB(urb));
-static void xpp_receive_callback(USB_PASS_CB(urb));
+static void xpp_send_callback(struct urb *urb);
+static void xpp_receive_callback(struct urb *urb);
 static int xusb_probe(struct usb_interface *interface,
 		      const struct usb_device_id *id);
 static void xusb_disconnect(struct usb_interface *interface);
@@ -869,7 +857,7 @@ static void xusb_disconnect(struct usb_interface *interface)
 	mutex_unlock(&protect_xusb_devices);
 }
 
-static void xpp_send_callback(USB_PASS_CB(urb))
+static void xpp_send_callback(struct urb *urb)
 {
 	struct uframe *uframe = urb_to_uframe(urb);
 	xframe_t *xframe = &uframe->xframe;
@@ -935,7 +923,7 @@ static void xpp_send_callback(USB_PASS_CB(urb))
 		XUSB_ERR(xusb, "A urb from non-connected device?\n");
 }
 
-static void xpp_receive_callback(USB_PASS_CB(urb))
+static void xpp_receive_callback(struct urb *urb)
 {
 	struct uframe *uframe = urb_to_uframe(urb);
 	xframe_t *xframe = &uframe->xframe;
@@ -1026,15 +1014,7 @@ static int __init xpp_usb_init(void)
 
 	xusb_cache =
 	    kmem_cache_create("xusb_cache", sizeof(xframe_t) + XFRAME_DATASIZE,
-#if (LINUX_VERSION_CODE == KERNEL_VERSION(2, 6, 22)) && defined(CONFIG_SLUB)
-			      0, SLAB_STORE_USER,
-#else
-			      0, 0,
-#endif
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 23)
-			      NULL,
-#endif
-			      NULL);
+			      0, 0, NULL);
 	if (!xusb_cache) {
 		ret = -ENOMEM;
 		goto failure;
diff --git a/include/dahdi/kernel.h b/include/dahdi/kernel.h
index be609db..363b613 100644
--- a/include/dahdi/kernel.h
+++ b/include/dahdi/kernel.h
@@ -60,43 +60,16 @@
 
 #define dahdi_pci_module pci_register_driver
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)
 #define DAHDI_IRQ_HANDLER(a) static irqreturn_t a(int irq, void *dev_id)
-#else
-#define DAHDI_IRQ_HANDLER(a) static irqreturn_t a(int irq, void *dev_id, struct pt_regs *regs)
-#endif
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
 #ifdef CONFIG_PCI
 #include <linux/pci-aspm.h>
 #endif
-#endif
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 29)
 #define HAVE_NET_DEVICE_OPS
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26)
-#  ifdef RHEL_RELEASE_VERSION
-#    if RHEL_RELEASE_CODE < RHEL_RELEASE_VERSION(5, 6)
-#define dev_name(dev)		((dev)->bus_id)
-#define dev_set_name(dev, format, ...) \
-	snprintf((dev)->bus_id, BUS_ID_SIZE, format, ## __VA_ARGS__)
-#    else
-#define dev_set_name(dev, format, ...) \
-	do { \
-		kobject_set_name(&(dev)->kobj, format, ## __VA_ARGS__); \
-		snprintf((dev)->bus_id, BUS_ID_SIZE, \
-			kobject_name(&(dev)->kobj));	\
-	} while (0)
-#    endif
-#  else
-#define dev_name(dev)		((dev)->bus_id)
-#define dev_set_name(dev, format, ...) \
-	snprintf((dev)->bus_id, BUS_ID_SIZE, format, ## __VA_ARGS__)
-#  endif
-#endif
-
 /* __dev* were removed in 3.8. They still have effect in 2.6.18. */
 #ifndef __devinit
 #  define __devinit
@@ -1476,100 +1449,9 @@ static inline void *PDE_DATA(const struct inode *inode)
 #endif
 #endif
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 31)
+
 #define KERN_CONT ""
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 27)
 
-#  ifndef RHEL_RELEASE_VERSION
-/* I'm not sure which 5.x release this was backported into. */
-static inline int try_wait_for_completion(struct completion *x)
-{
-	unsigned long flags;
-	int ret = 1;
-
-	spin_lock_irqsave(&x->wait.lock, flags);
-	if (!x->done)
-		ret = 0;
-	else
-		x->done--;
-	spin_unlock_irqrestore(&x->wait.lock, flags);
-	return ret;
-}
-#endif
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26)
-#ifdef CONFIG_PROC_FS
-#include <linux/proc_fs.h>
-static inline struct proc_dir_entry *proc_create_data(const char *name,
-					mode_t mode,
-					struct proc_dir_entry *parent,
-					const struct file_operations *proc_fops,
-					void *data)
-{
-	struct proc_dir_entry *pde = create_proc_entry(name, mode, parent);
-	if (!pde)
-		return NULL;
-	pde->proc_fops = proc_fops;
-	pde->data = data;
-	return pde;
-}
-#endif /* CONFIG_PROC_FS */
-#ifndef clamp
-#define clamp(x, low, high) min(max(low, x), high)
-#endif
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 25)
-
-/* Some distributions backported fatal_signal_pending so we'll use a macro to
- * override the inline function definition. */
-#define fatal_signal_pending(p) \
-	(signal_pending((p)) && sigismember(&(p)->pending.signal, SIGKILL))
-
-#ifdef CONFIG_PCI
-#ifndef PCIE_LINK_STATE_L0S
-#define PCIE_LINK_STATE_L0S	1
-#define PCIE_LINK_STATE_L1	2
-#define PCIE_LINK_STATE_CLKPM	4
-#endif
-#define pci_disable_link_state dahdi_pci_disable_link_state
-void dahdi_pci_disable_link_state(struct pci_dev *pdev, int state);
-#endif /* CONFIG_PCI */
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 22)
-
-#define list_first_entry(ptr, type, member) \
-	list_entry((ptr)->next, type, member)
-
-#define strncasecmp strnicmp
-
-#ifndef __packed
-#define __packed  __attribute__((packed))
-#endif 
-
-#include <linux/ctype.h>
-/* A define of 'clamp_val' happened to be added in the patch
- * linux-2.6-sata-prep-work-for-rhel5-3.patch kernel-2.6.spec that also
- * backported support for strcasecmp to some later RHEL/Centos kernels.
- * If you have an older kernel that breaks because strcasecmp is already
- * defined, somebody out-smarted us. In that case, replace the line below
- * with '#if 0' to get the code building, and file a bug report at
- * https://issues.asterisk.org/ .
- */
-#ifndef clamp_val
-static inline int strcasecmp(const char *s1, const char *s2)
-{
-	int c1, c2;
-
-	do {
-		c1 = tolower(*s1++);
-		c2 = tolower(*s2++);
-	} while (c1 == c2 && c1 != 0);
-	return c1 - c2;
-}
-#endif /* clamp_val */
-
-#endif /* 2.6.22 */
-#endif /* 2.6.25 */
-#endif /* 2.6.26 */
-#endif /* 2.6.27 */
 #endif /* 2.6.31 */
 #endif /* 3.10.0 */
 #endif /* 3.16.0 */