On 11/10/2015 02:59 PM, Mirza Krak wrote: > From: Mirza Krak <mirza.k...@hostmobility.com> > > 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
This problem occurs only an hardware, where the SJA1000 is powered during system suspend? > - 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. Doesn't the SJA1000 trigger an interrupt that is detected after resuming? You add the fix to the open() function, which is triggered during $(ifconfig up), how is related to suspend/resume? Does the network layer call $(ifconfig down) during shutdown? There isn't any suspend/resume code in the sja1000 driver, for me it seems that we should add resume code that handles this problem. > > Signed-off-by: Mirza Krak <mirza.k...@hostmobility.com> > --- > 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 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); > } > Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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