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authorStanislav Yakovlev <stas.yakovlev@gmail.com>2012-04-19 15:55:09 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-07 08:56:40 -0700
commitb00c5b8d8590a0fe2713a4bee24e9562480ccb9e (patch)
tree18b0ccebf6db040babda8beebedcfb719d20e17a
parentb476e58a834f099aa0f7b4d0a71853e6c61ee6d8 (diff)
ipw2200: Fix race condition in the command completion acknowledge
commit dd447319895d0c0af423e483d9b63f84f3f8869a upstream. 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 roaming (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. Signed-off-by: Stanislav Yakovlev <stas.yakovlev@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/wireless/ipw2x00/ipw2200.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/net/wireless/ipw2x00/ipw2200.c b/drivers/net/wireless/ipw2x00/ipw2200.c
index 87813c33bdc2..b2707d733e92 100644
--- a/drivers/net/wireless/ipw2x00/ipw2200.c
+++ b/drivers/net/wireless/ipw2x00/ipw2200.c
@@ -2182,6 +2182,7 @@ 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) {
@@ -2223,10 +2224,20 @@ 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) {