kernel/ipw2200-Fix-race-condition-in-the-command-completion-acknowledge.patch
2012-04-24 08:53:19 -04:00

69 lines
2.4 KiB
Diff

Driver incorrectly validates command completion: instead of waiting
for a command to be acknowledged it continues execution. Most of the
time driver gets acknowledge of the command completion in a tasklet
before it executes the next one. But sometimes it sends the next
command before it gets acknowledge for the previous one. In such a
case one of the following error messages appear in the log:
Failed to send SYSTEM_CONFIG: Already sending a command.
Failed to send ASSOCIATE: Already sending a command.
Failed to send TX_POWER: Already sending a command.
After that you need to reload the driver to get it working again.
This bug occurs during roammaping (reported by Sam Varshavchik)
https://bugzilla.redhat.com/show_bug.cgi?id=738508
and machine booting (reported by Tom Gundersen and Mads Kiilerich)
https://bugs.archlinux.org/task/28097
https://bugzilla.redhat.com/show_bug.cgi?id=802106
This patch doesn't fix the delay issue during firmware load.
But at least device now works as usual after boot.
Cc: stable@kernel.org
Signed-off-by: Stanislav Yakovlev <stas.yakovlev@gmail.com>
---
drivers/net/wireless/ipw2x00/ipw2200.c | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletions(-)
diff --git a/drivers/net/wireless/ipw2x00/ipw2200.c b/drivers/net/wireless/ipw2x00/ipw2200.c
index 4130802..8cbafa5 100644
--- a/drivers/net/wireless/ipw2x00/ipw2200.c
+++ b/drivers/net/wireless/ipw2x00/ipw2200.c
@@ -2192,6 +2192,7 @@ static int __ipw_send_cmd(struct ipw_priv *priv, struct host_cmd *cmd)
{
int rc = 0;
unsigned long flags;
+ unsigned long now, end;
spin_lock_irqsave(&priv->lock, flags);
if (priv->status & STATUS_HCMD_ACTIVE) {
@@ -2233,10 +2234,20 @@ static int __ipw_send_cmd(struct ipw_priv *priv, struct host_cmd *cmd)
}
spin_unlock_irqrestore(&priv->lock, flags);
+ now = jiffies;
+ end = now + HOST_COMPLETE_TIMEOUT;
+again:
rc = wait_event_interruptible_timeout(priv->wait_command_queue,
!(priv->
status & STATUS_HCMD_ACTIVE),
- HOST_COMPLETE_TIMEOUT);
+ end - now);
+ if (rc < 0) {
+ now = jiffies;
+ if (time_before(now, end))
+ goto again;
+ rc = 0;
+ }
+
if (rc == 0) {
spin_lock_irqsave(&priv->lock, flags);
if (priv->status & STATUS_HCMD_ACTIVE) {
--
1.7.2.5
--
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