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authorMarc Kleine-Budde <mkl@pengutronix.de>2013-11-24 23:31:24 +0100
committerMarc Kleine-Budde <mkl@pengutronix.de>2013-11-25 21:48:51 +0100
commite35d46adc49b469fd92bdb64fea8af93640e6651 (patch)
tree450dc5d0e82ae23c24cdd2374ba578f904b81b2f /drivers/net/can/c_can
parent2fea6cd303c0d0cd9067da31d873b6a6d5bd75e7 (diff)
downloadtalos-obmc-linux-e35d46adc49b469fd92bdb64fea8af93640e6651.tar.gz
talos-obmc-linux-e35d46adc49b469fd92bdb64fea8af93640e6651.zip
can: c_can: don't call pm_runtime_get_sync() from interrupt context
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 <AGlen@bepmarine.com> Tested-by: Andrew Glen <AGlen@bepmarine.com> Signed-off-by: Andrew Glen <AGlen@bepmarine.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/c_can')
-rw-r--r--drivers/net/can/c_can/c_can.c21
1 files 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 e3fc07cf2f62..e59c42b446a9 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;
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