From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrew Glen , Marc Kleine-Budde Subject: [PATCH 3.10 19/52] can: c_can: dont call pm_runtime_get_sync() from interrupt context Date: Tue, 10 Dec 2013 00:00:52 -0800 Message-Id: <20131210075955.553610457@linuxfoundation.org> In-Reply-To: <20131210075954.196229872@linuxfoundation.org> References: <20131210075954.196229872@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Kleine-Budde commit e35d46adc49b469fd92bdb64fea8af93640e6651 upstream. 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 Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/c_can/c_can.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) --- 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_dev 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(str 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;