Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757290Ab2EIF5S (ORCPT ); Wed, 9 May 2012 01:57:18 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39102 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756915Ab2EIFxv (ORCPT ); Wed, 9 May 2012 01:53:51 -0400 Message-Id: <20120509055049.342511242@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Wed, 09 May 2012 06:52:52 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Stanislav Yakovlev , "John W. Linville" Subject: [ 143/167] [PATCH] ipw2200: Fix race condition in the command completion acknowledge In-Reply-To: <20120509055029.588587017@decadent.org.uk> X-SA-Exim-Connect-IP: 192.168.4.185 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2812 Lines: 81 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stanislav Yakovlev 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 Signed-off-by: John W. Linville Signed-off-by: Ben Hutchings --- drivers/net/wireless/ipw2x00/ipw2200.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ipw2x00/ipw2200.c b/drivers/net/wireless/ipw2x00/ipw2200.c index 2b02257..1779db3 100644 --- a/drivers/net/wireless/ipw2x00/ipw2200.c +++ b/drivers/net/wireless/ipw2x00/ipw2200.c @@ -2191,6 +2191,7 @@ 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) { @@ -2232,10 +2233,20 @@ 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) { -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/