Return-path: Received: from mail.atheros.com ([12.36.123.2]:22974 "EHLO mail.atheros.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754660Ab0DPGYl (ORCPT ); Fri, 16 Apr 2010 02:24:41 -0400 Received: from mail.atheros.com ([10.10.20.105]) by sidewinder.atheros.com for ; Thu, 15 Apr 2010 23:24:41 -0700 From: Sujith MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Message-ID: <19400.641.785333.69038@gargle.gargle.HOWL> Date: Fri, 16 Apr 2010 11:54:01 +0530 To: CC: Subject: [PATCH 09/10] ath9k_htc: Handle WMI timeouts properly Sender: linux-wireless-owner@vger.kernel.org List-ID: If a WMI command has timed out for some reason, a late WMI response would end up updating the response region of a new WMI request that has been issued in the meantime. Fix this race condition by dropping a WMI response if a new WMI command has been issued. Signed-off-by: Sujith --- drivers/net/wireless/ath/ath9k/wmi.c | 13 +++++++++++++ drivers/net/wireless/ath/ath9k/wmi.h | 1 + 2 files changed, 14 insertions(+), 0 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c index 355e0db..afbf63d 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.c +++ b/drivers/net/wireless/ath/ath9k/wmi.c @@ -204,6 +204,14 @@ static void ath9k_wmi_ctrl_rx(void *priv, struct sk_buff *skb, return; } + /* Check if there has been a timeout. */ + spin_lock(&wmi->wmi_lock); + if (cmd_id != wmi->last_cmd_id) { + spin_unlock(&wmi->wmi_lock); + goto free_skb; + } + spin_unlock(&wmi->wmi_lock); + /* WMI command response */ ath9k_wmi_rsp_callback(wmi, skb); @@ -266,6 +274,7 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id, struct sk_buff *skb; u8 *data; int time_left, ret = 0; + unsigned long flags; if (!wmi) return -EINVAL; @@ -297,6 +306,10 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id, if (ret) goto out; + spin_lock_irqsave(&wmi->wmi_lock, flags); + wmi->last_cmd_id = cmd_id; + spin_unlock_irqrestore(&wmi->wmi_lock, flags); + time_left = wait_for_completion_timeout(&wmi->cmd_wait, timeout); if (!time_left) { ath_print(common, ATH_DBG_WMI, diff --git a/drivers/net/wireless/ath/ath9k/wmi.h b/drivers/net/wireless/ath/ath9k/wmi.h index fd8c9c5..6113571 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.h +++ b/drivers/net/wireless/ath/ath9k/wmi.h @@ -97,6 +97,7 @@ struct wmi { enum htc_endpoint_id ctrl_epid; struct mutex op_mutex; struct completion cmd_wait; + enum wmi_cmd_id last_cmd_id; u16 tx_seq_id; u8 *cmd_rsp_buf; u32 cmd_rsp_len; -- 1.7.0.5