From: Sujith <Sujith.Manoharan@atheros.com>
To: <linville@tuxdriver.com>
Cc: <linux-wireless@vger.kernel.org>
Subject: [PATCH 1/2] ath9k_htc: Fix WMI command race
Date: Thu, 22 Apr 2010 14:58:18 +0530 [thread overview]
Message-ID: <19408.5810.511895.284103@gargle.gargle.HOWL> (raw)
My patch "ath9k_htc: Handle WMI timeouts properly" introduced
a race condition in WMI command processing. The last issued command
should be stored _before_ issuing a WMI command. Not doing this
would result in the WMI event IRQ dropping correct command responses
as invalid.
Fix this race by storing the command id correctly.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
---
drivers/net/wireless/ath/ath9k/wmi.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index c688545..e23172c 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -305,14 +305,14 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id,
wmi->cmd_rsp_buf = rsp_buf;
wmi->cmd_rsp_len = rsp_len;
- ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len);
- if (ret)
- goto out;
-
spin_lock_irqsave(&wmi->wmi_lock, flags);
wmi->last_cmd_id = cmd_id;
spin_unlock_irqrestore(&wmi->wmi_lock, flags);
+ ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len);
+ if (ret)
+ goto out;
+
time_left = wait_for_completion_timeout(&wmi->cmd_wait, timeout);
if (!time_left) {
ath_print(common, ATH_DBG_WMI,
--
1.7.0.5
reply other threads:[~2010-04-22 9:28 UTC|newest]
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