From 9fd43e01392b3ab19ed12e81fabb5cc5fce81199 Mon Sep 17 00:00:00 2001
From: Shaun Ruffell <sruffell@digium.com>
Date: Tue, 26 Jul 2011 20:19:30 +0000
Subject: [PATCH] wctc4xxp: Cleanup in-flight commands when halting due to
 hardware error.

On one system I was seeing the board reset in the middle of a
transaction. Any commands that were on the response list when this would
happen would never be completed and the process would then be stuck in
an uninterruptible sleep. This change also prevents the driver from
sleeping in timer context, which would result in a kernel panic.

This change at least lets an error message propogate back to the user.

DAHDI-880

Signed-off-by: Shaun Ruffell <sruffell@digium.com>

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@10082 a0bf4364-ded3-4de4-8d8a-66a801d63aff
---
 drivers/dahdi/wctc4xxp/base.c | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/drivers/dahdi/wctc4xxp/base.c b/drivers/dahdi/wctc4xxp/base.c
index 893a104..2ed2147 100644
--- a/drivers/dahdi/wctc4xxp/base.c
+++ b/drivers/dahdi/wctc4xxp/base.c
@@ -1614,6 +1614,20 @@ wctc4xxp_transmit_cmd(struct wcdte *wc, struct tcb *cmd)
 {
 	int res;
 
+	/* If we're shutdown all commands will timeout. Just complete the
+	 * command here with the timeout flag */
+	if (unlikely(test_bit(DTE_SHUTDOWN, &wc->flags))) {
+		if (cmd->flags & DO_NOT_AUTO_FREE) {
+			cmd->flags |= DTE_CMD_TIMEOUT;
+			list_del_init(&cmd->node);
+			complete(&cmd->complete);
+		} else {
+			list_del(&cmd->node);
+			free_cmd(cmd);
+		}
+		return;
+	}
+
 	if (cmd->data_len < MIN_PACKET_LEN) {
 		memset((u8 *)(cmd->data) + cmd->data_len, 0,
 		       MIN_PACKET_LEN-cmd->data_len);
@@ -2740,11 +2754,10 @@ wctc4xxp_start_dma(struct wcdte *wc)
 }
 
 static void
-wctc4xxp_stop_dma(struct wcdte *wc)
+_wctc4xxp_stop_dma(struct wcdte *wc)
 {
 	/* Disable interrupts and reset */
 	unsigned int reg;
-	unsigned long newjiffies;
 	/* Disable interrupts */
 	wctc4xxp_setintmask(wc, 0x00000000);
 	wctc4xxp_setctl(wc, 0x0084, 0x00000000);
@@ -2753,7 +2766,14 @@ wctc4xxp_stop_dma(struct wcdte *wc)
 	reg = wctc4xxp_getctl(wc, 0x0000);
 	reg |= 0x00000001;
 	wctc4xxp_setctl(wc, 0x0000, reg);
+}
 
+static void
+wctc4xxp_stop_dma(struct wcdte *wc)
+{
+	unsigned long newjiffies;
+
+	_wctc4xxp_stop_dma(wc);
 	newjiffies = jiffies + HZ; /* One second timeout */
 	/* We'll wait here for the part to come out of reset */
 	while (((wctc4xxp_getctl(wc, 0x0000)) & 0x00000001) &&
@@ -2761,7 +2781,6 @@ wctc4xxp_stop_dma(struct wcdte *wc)
 			msleep(1);
 }
 
-
 #define MDIO_SHIFT_CLK		0x10000
 #define MDIO_DATA_WRITE1 	0x20000
 #define MDIO_ENB		0x00000
@@ -3305,13 +3324,19 @@ wctc4xxp_watchdog(unsigned long data)
 		if (time_after(jiffies, cmd->timeout)) {
 			if (++cmd->retries > MAX_RETRIES) {
 				if (!(cmd->flags & TX_COMPLETE)) {
+
+					cmd->flags |= DTE_CMD_TIMEOUT;
+					list_del_init(&cmd->node);
+					complete(&cmd->complete);
+
 					set_bit(DTE_SHUTDOWN, &wc->flags);
 					spin_unlock(&wc->cmd_list_lock);
-					wctc4xxp_stop_dma(wc);
+					_wctc4xxp_stop_dma(wc);
 					dev_err(&wc->pdev->dev,
 					  "Board malfunctioning.  " \
 					  "Halting operation.\n");
-					return;
+					reschedule_timer = 0;
+					break;
 				}
 				/* ERROR:  We've retried the command and
 				 * haven't received the ACK or the response.