From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: [PATCH] can: sja1000 fix isr hang when hw is unplugged under load Date: Tue, 14 Feb 2012 20:27:09 +0100 Message-ID: <4F3AB58D.60309@hartkopp.net> References: <1318506157-10329-1-git-send-email-mkl@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mo-p00-ob.rzone.de ([81.169.146.160]:30658 "EHLO mo-p00-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759855Ab2BNT1K (ORCPT ); Tue, 14 Feb 2012 14:27:10 -0500 Received: from [192.168.178.40] (p5B0B117C.dip0.t-ipconnect.de [91.11.17.124]) by smtp.strato.de (klopstock mo40) (RZmta 27.6 DYNA|AUTH) with ESMTPA id L042ado1EITc86 for ; Tue, 14 Feb 2012 20:26:55 +0100 (MET) In-Reply-To: <1318506157-10329-1-git-send-email-mkl@pengutronix.de> Sender: linux-can-owner@vger.kernel.org List-ID: To: linux-can@vger.kernel.org In the case of hotplug enabled devices (PCMCIA/PCIeC) the removal of the hardware can cause an infinite loop in the common sja1000 isr. Use the already retrieved status register to indicate a possible hardware removal and double check by reading the mode register in sja1000_probe_chip. Signed-off-by: Oliver Hartkopp --- diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index ebbcfca..37773fb 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -492,6 +492,9 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id) while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) { n++; status = priv->read_reg(priv, REG_SR); + /* check for absent controller due to hw unplug */ + if (status == 0xFF && !sja1000_probe_chip(dev)) + return IRQ_NONE; if (isrc & IRQ_WUI) netdev_warn(dev, "wakeup interrupt\n"); @@ -508,6 +511,9 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id) while (status & SR_RBS) { sja1000_rx(dev); status = priv->read_reg(priv, REG_SR); + /* check for absent controller */ + if (status == 0xFF && !sja1000_probe_chip(dev)) + return IRQ_NONE; } } if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {