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> --- 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
