On Sun, Jun 20, 2021 at 11:04:23PM +0200, Wolfram Sang wrote: > On Fri, Jun 04, 2021 at 04:27:44PM -0700, Stephen Boyd wrote: > > From: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> > > > > If an i2c client receives an interrupt during reboot or shutdown it may > > be too late to service it by making an i2c transaction on the bus > > because the i2c controller has already been shutdown. This can lead to > > system hangs if the i2c controller tries to make a transfer that is > > doomed to fail because the access to the i2c pins is already shut down, > > or an iommu translation has been torn down so i2c controller register > > access doesn't work. > > > > Let's simply disable the irq if there isn't a shutdown callback for an > > i2c client when there is an irq associated with the device. This will > > make sure that irqs don't come in later than the time that we can handle > > it. We don't do this if the i2c client device already has a shutdown > > callback because presumably they're doing the right thing and quieting > > the device so irqs don't come in after the shutdown callback returns. > > > > Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > [swboyd@xxxxxxxxxxxx: Dropped newline, added commit text, added > > interrupt.h for robot build error] > > Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> > > I think this is for-current material because it fixes hangs. Or better > for-next to check for side-effects? > We lived with this issue for many years, so letting it cook in next will not hurt us IMO. Thanks. -- Dmitry
