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> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> > --- > > Dmitry, please add Signed-off-by so this can be merged through i2c > > This supersedes https://lore.kernel.org/r/20210510220012.2003285-1-swboyd@xxxxxxxxxxxx > > Changes from v1 (https://lore.kernel.org/r/20210604212752.3547301-1-swboyd@xxxxxxxxxxxx) > * Add interrupt.h include for robot > > drivers/i2c/i2c-core-base.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 5a97e4a02fa2..e314ccaf114a 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -24,6 +24,7 @@ > #include <linux/i2c-smbus.h> > #include <linux/idr.h> > #include <linux/init.h> > +#include <linux/interrupt.h> > #include <linux/irqflags.h> > #include <linux/jump_label.h> > #include <linux/kernel.h> > @@ -627,6 +628,8 @@ static void i2c_device_shutdown(struct device *dev) > driver = to_i2c_driver(dev->driver); > if (driver->shutdown) > driver->shutdown(client); > + else if (client->irq > 0) > + disable_irq(client->irq); > } > > static void i2c_client_dev_release(struct device *dev) > > base-commit: 8124c8a6b35386f73523d27eacb71b5364a68c4c > -- > https://chromeos.dev > -- Dmitry
