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authorMirza Krak <mirza.krak@hostmobility.com>2015-11-10 14:59:34 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-09 14:34:30 -0500
commitbf804ca6bcbb73b7c6ab2328f4baadd0e1f1f2d8 (patch)
tree2d26f38a6c70d3c59ee45b4f4895d12b5003e174
parent8d66c7371044032029efd1aecfc9a3b3e2125a9d (diff)
can: sja1000: clear interrupts on start
commit 7cecd9ab80f43972c056dc068338f7bcc407b71c upstream. According to SJA1000 data sheet error-warning (EI) interrupt is not cleared by setting the controller in to reset-mode. Then if we have the following case: - system is suspended (echo mem > /sys/power/state) and SJA1000 is left in operating state - A bus error condition occurs which activates EI interrupt, system is still suspended which means EI interrupt will be not be handled nor cleared. If the above two events occur, on resume there is no way to return the SJA1000 to operating state, except to cycle power to it. By simply reading the IR register on start we will clear any previous conditions that could be present. Signed-off-by: Mirza Krak <mirza.krak@hostmobility.com> Reported-by: Christian Magnusson <Christian.Magnusson@semcon.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/can/sja1000/sja1000.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 7b92e911a616..f10834be48a5 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -218,6 +218,9 @@ static void sja1000_start(struct net_device *dev)
priv->write_reg(priv, SJA1000_RXERR, 0x0);
priv->read_reg(priv, SJA1000_ECC);
+ /* clear interrupt flags */
+ priv->read_reg(priv, SJA1000_IR);
+
/* leave reset mode */
set_normal_mode(dev);
}