Return-path: Received: from queueout02-winn.ispmail.ntl.com ([81.103.221.56]:25028 "EHLO queueout02-winn.ispmail.ntl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752062Ab1JCLVd (ORCPT ); Mon, 3 Oct 2011 07:21:33 -0400 From: Daniel Drake To: linville@tuxdriver.com Cc: dcbw@redhat.com Cc: linux-wireless@vger.kernel.org Cc: libertas-dev@lists.infradead.org Subject: [PATCH v2] libertas: detect TX lockups and reset hardware Message-Id: <20111003103302.644D79D401D@zog.reactivated.net> (sfid-20111003_132137_189331_44DE1CF0) Date: Mon, 3 Oct 2011 11:33:02 +0100 (BST) Sender: linux-wireless-owner@vger.kernel.org List-ID: Recent patches added support for resetting the SD8686 hardware when commands time out, which seems to happen quite frequently soon after resuming the system from a Wake-on-WLAN-triggered resume. At http://dev.laptop.org/ticket/10969 we see the same thing happen with transmits. In this case, the hardware will fail to respond to a frame passed for transmission, and libertas (correctly) will block all further commands and transmissions as the hardware can only deal with one thing at a time. This results in a lockup while the system waits indefinitely for the dead card to respond. Hook up a TX lockup timer to detect this and reset the hardware. Signed-off-by: Daniel Drake --- drivers/net/wireless/libertas/dev.h | 1 + drivers/net/wireless/libertas/main.c | 35 ++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 0 deletions(-) v2: regenerated against wireless-next.git. Compared to the first version, minor changes were needed to the way the timer is stopped when the interface is brought down (these routines changed as a result of other recent work). diff --git a/drivers/net/wireless/libertas/dev.h b/drivers/net/wireless/libertas/dev.h index fb3e40b..f3fd447 100644 --- a/drivers/net/wireless/libertas/dev.h +++ b/drivers/net/wireless/libertas/dev.h @@ -158,6 +158,7 @@ struct lbs_private { /* protected by hard_start_xmit serialization */ u8 txretrycount; struct sk_buff *currenttxskb; + struct timer_list tx_lockup_timer; /* Locks */ struct mutex lock; diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c index d62d1fb..6a32623 100644 --- a/drivers/net/wireless/libertas/main.c +++ b/drivers/net/wireless/libertas/main.c @@ -188,6 +188,7 @@ int lbs_stop_iface(struct lbs_private *priv) spin_unlock_irqrestore(&priv->driver_lock, flags); cancel_work_sync(&priv->mcast_work); + del_timer_sync(&priv->tx_lockup_timer); /* Disable command processing, and wait for all commands to complete */ lbs_deb_main("waiting for commands to complete\n"); @@ -243,6 +244,7 @@ void lbs_host_to_card_done(struct lbs_private *priv) lbs_deb_enter(LBS_DEB_THREAD); spin_lock_irqsave(&priv->driver_lock, flags); + del_timer(&priv->tx_lockup_timer); priv->dnld_sent = DNLD_RES_RECEIVED; @@ -585,6 +587,9 @@ static int lbs_thread(void *data) if (ret) { lbs_deb_tx("host_to_card failed %d\n", ret); priv->dnld_sent = DNLD_RES_RECEIVED; + } else { + mod_timer(&priv->tx_lockup_timer, + jiffies + (HZ * 5)); } priv->tx_pending_len = 0; if (!priv->currenttxskb) { @@ -601,6 +606,7 @@ static int lbs_thread(void *data) } del_timer(&priv->command_timer); + del_timer(&priv->tx_lockup_timer); del_timer(&priv->auto_deepsleep_timer); lbs_deb_leave(LBS_DEB_THREAD); @@ -735,6 +741,32 @@ out: } /** + * lbs_tx_lockup_handler - handles the timeout of the passing of TX frames + * to the hardware. This is known to frequently happen with SD8686 when + * waking up after a Wake-on-WLAN-triggered resume. + * + * @data: &struct lbs_private pointer + */ +static void lbs_tx_lockup_handler(unsigned long data) +{ + struct lbs_private *priv = (struct lbs_private *)data; + unsigned long flags; + + lbs_deb_enter(LBS_DEB_TX); + spin_lock_irqsave(&priv->driver_lock, flags); + + netdev_info(priv->dev, "TX lockup detected\n"); + if (priv->reset_card) + priv->reset_card(priv); + + priv->dnld_sent = DNLD_RES_RECEIVED; + wake_up_interruptible(&priv->waitq); + + spin_unlock_irqrestore(&priv->driver_lock, flags); + lbs_deb_leave(LBS_DEB_TX); +} + +/** * auto_deepsleep_timer_fn - put the device back to deep sleep mode when * timer expires and no activity (command, event, data etc.) is detected. * @data: &struct lbs_private pointer @@ -820,6 +852,8 @@ static int lbs_init_adapter(struct lbs_private *priv) setup_timer(&priv->command_timer, lbs_cmd_timeout_handler, (unsigned long)priv); + setup_timer(&priv->tx_lockup_timer, lbs_tx_lockup_handler, + (unsigned long)priv); setup_timer(&priv->auto_deepsleep_timer, auto_deepsleep_timer_fn, (unsigned long)priv); @@ -857,6 +891,7 @@ static void lbs_free_adapter(struct lbs_private *priv) lbs_free_cmd_buffer(priv); kfifo_free(&priv->event_fifo); del_timer(&priv->command_timer); + del_timer(&priv->tx_lockup_timer); del_timer(&priv->auto_deepsleep_timer); lbs_deb_leave(LBS_DEB_MAIN); -- 1.7.6.4