From 6ce34ec11c6297562e70e27c57a24cd27d4cd2b1 Mon Sep 17 00:00:00 2001 From: Sujith Date: Fri, 16 Apr 2010 11:54:01 +0530 Subject: [PATCH] ath9k_htc: Handle WMI timeouts properly 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 Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath9k/wmi.c | 13 +++++++++++++ drivers/net/wireless/ath/ath9k/wmi.h | 1 + 2 files changed, 14 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c index 355e0dbf3c66..afbf63daf551 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 fd8c9c5f4a05..611357158ecf 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; -- 2.20.1