From: Mirza Krak <mirza.krak@xxxxxxxxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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@xxxxxxxxxxxxxxxx> Reported-by: Christian Magnusson <Christian.Magnusson@xxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/net/can/sja1000/sja1000.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index f17c3018b7c7..c2d0559115d3 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -184,6 +184,9 @@ 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); } -- 2.6.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html