From patchwork Wed Nov 27 21:11:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 294658 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E5D552C00AB for ; Thu, 28 Nov 2013 08:12:14 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757829Ab3K0VLy (ORCPT ); Wed, 27 Nov 2013 16:11:54 -0500 Received: from metis.ext.pengutronix.de ([92.198.50.35]:49155 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757681Ab3K0VLv (ORCPT ); Wed, 27 Nov 2013 16:11:51 -0500 Received: from gallifrey.ext.pengutronix.de ([2001:6f8:1178:4:5054:ff:fe8d:eefb] helo=hardanger.do.blackshift.org) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1VlmOg-0004qw-Ud; Wed, 27 Nov 2013 22:11:47 +0100 From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, Marc Kleine-Budde , Andrew Glen , linux-stable Subject: [PATCH 2/4] can: c_can: don't call pm_runtime_get_sync() from interrupt context Date: Wed, 27 Nov 2013 22:11:33 +0100 Message-Id: <1385586695-11134-3-git-send-email-mkl@pengutronix.de> X-Mailer: git-send-email 1.8.5.rc0 In-Reply-To: <1385586695-11134-1-git-send-email-mkl@pengutronix.de> References: <1385586695-11134-1-git-send-email-mkl@pengutronix.de> X-SA-Exim-Connect-IP: 2001:6f8:1178:4:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The c_can driver contians a callpath (c_can_poll -> c_can_state_change -> c_can_get_berr_counter) which may call pm_runtime_get_sync() from the IRQ handler, which is not allowed and results in "BUG: scheduling while atomic". This problem is fixed by introducing __c_can_get_berr_counter, which will not call pm_runtime_get_sync(). Reported-by: Andrew Glen Tested-by: Andrew Glen Signed-off-by: Andrew Glen Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/c_can/c_can.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index e3fc07c..e59c42b 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -712,22 +712,31 @@ static int c_can_set_mode(struct net_device *dev, enum can_mode mode) return 0; } -static int c_can_get_berr_counter(const struct net_device *dev, - struct can_berr_counter *bec) +static int __c_can_get_berr_counter(const struct net_device *dev, + struct can_berr_counter *bec) { unsigned int reg_err_counter; struct c_can_priv *priv = netdev_priv(dev); - c_can_pm_runtime_get_sync(priv); - reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG); bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >> ERR_CNT_REC_SHIFT; bec->txerr = reg_err_counter & ERR_CNT_TEC_MASK; + return 0; +} + +static int c_can_get_berr_counter(const struct net_device *dev, + struct can_berr_counter *bec) +{ + struct c_can_priv *priv = netdev_priv(dev); + int err; + + c_can_pm_runtime_get_sync(priv); + err = __c_can_get_berr_counter(dev, bec); c_can_pm_runtime_put_sync(priv); - return 0; + return err; } /* @@ -872,7 +881,7 @@ static int c_can_handle_state_change(struct net_device *dev, if (unlikely(!skb)) return 0; - c_can_get_berr_counter(dev, &bec); + __c_can_get_berr_counter(dev, &bec); reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG); rx_err_passive = (reg_err_counter & ERR_CNT_RP_MASK) >> ERR_CNT_RP_SHIFT;