[PATCH] Fix for the IPMI SMB driver

From: Corey Minyard
Date: Tue Feb 22 2005 - 14:30:20 EST



The IPMI SMB driver, when running in run-to-completion mode
(done during panic time), would sometimes get locked up if
a timeout occurred because the timer would not get run
properly. This adds the timer handling to the run-to-completion
code.

Signed-off-by: Corey Minyard <minyard@xxxxxxx>

Index: linux-2.6.11-rc4/drivers/char/ipmi/ipmi_smb.c
===================================================================
--- linux-2.6.11-rc4.orig/drivers/char/ipmi/ipmi_smb.c
+++ linux-2.6.11-rc4/drivers/char/ipmi/ipmi_smb.c
@@ -140,6 +140,10 @@
sure stuff goes out. */
int run_to_completion;

+ /* Used to perform timer operations when run-to-completion
+ mode is on. This is a countdown timer. */
+ int rtc_us_timer;
+
/* Used for sending/receiving data. +1 for the length. */
unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
unsigned int data_len;
@@ -322,6 +326,8 @@
struct smb_info *smb_info = (void *) data;
struct i2c_op_q_entry *i2ce;

+ smb_info->rtc_us_timer = 0;
+
i2ce = &smb_info->i2c_q_entry;
i2ce->xfer_type = I2C_OP_SMBUS;
i2ce->handler = msg_done_handler;
@@ -380,6 +386,7 @@
t->data = (unsigned long) smb_info;
t->function = retry_timeout;
add_timer(t);
+ smb_info->rtc_us_timer = 10000;
return;
}
if (smb_info->smb_debug & SMB_DEBUG_MSG)
@@ -790,6 +797,13 @@
i2c_poll(&smb_info->client, 0);
while (! SMB_IDLE(smb_info)) {
udelay(500);
+ if (smb_info->rtc_us_timer > 0) {
+ smb_info->rtc_us_timer -= 500;
+ if (smb_info->rtc_us_timer <= 0) {
+ retry_timeout((unsigned long) smb_info);
+ del_timer(&smb_info->retry_timer);
+ }
+ }
i2c_poll(&smb_info->client, 500);
}
return;
@@ -856,6 +870,13 @@
i2c_poll(&smb_info->client, 0);
while (! SMB_IDLE(smb_info)) {
udelay(500);
+ if (smb_info->rtc_us_timer > 0) {
+ smb_info->rtc_us_timer -= 500;
+ if (smb_info->rtc_us_timer <= 0) {
+ retry_timeout((unsigned long) smb_info);
+ del_timer(&smb_info->retry_timer);
+ }
+ }
i2c_poll(&smb_info->client, 500);
}
}