Hi, On Fri, 2018-12-21 at 09:52 -0800, Florian Fainelli wrote: > On 12/21/18 4:11 AM, Paul Kocialkowski wrote: > > The driver's interrupt handler checks whether a message is currently > > being handled with the curr_msg pointer. When it is NULL, the interrupt > > is considered to be unexpected. Similarly, the i2c_start_transfer > > routine checks for the remaining number of messages to handle in > > num_msgs. > > > > However, these values are never cleared and always keep the message and > > number relevant to the latest transfer (which might be done already and > > the underlying message memory might have been freed). > > > > When an unexpected interrupt hits with the DONE bit set, the isr will > > then try to access the flags field of the curr_msg structure, leading > > to a fatal page fault. > > > > Fix the issue by systematically clearing curr_msg and num_msgs in the > > driver-wide device structure when a transfer is considered complete. > > Should not this get a Fixes tag? Yes it totally should! Thanks for the suggestion. Cheers, Paul > > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> > > --- > > drivers/i2c/busses/i2c-bcm2835.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c > > index 44deae78913e..5486252f5f2f 100644 > > --- a/drivers/i2c/busses/i2c-bcm2835.c > > +++ b/drivers/i2c/busses/i2c-bcm2835.c > > @@ -298,6 +298,9 @@ static int bcm2835_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], > > return -ETIMEDOUT; > > } > > > > + i2c_dev->curr_msg = NULL; > > + i2c_dev->num_msgs = 0; > > + > > if (!i2c_dev->msg_err) > > return num; > > > > > > -- Paul Kocialkowski, Bootlin (formerly Free Electrons) Embedded Linux and kernel engineering https://bootlin.com
