We are racing the registering of .to_irq when probing the i2c driver. This results in random failure of touchscreen devices. Following errors could be seen in dmesg logs when gc->to_irq is NULL [2.101857] i2c_hid i2c-FTS3528:00: HID over i2c has not been provided an Int IRQ [2.101953] i2c_hid: probe of i2c-FTS3528:00 failed with error -22 To avoid this situation, defer probing until to_irq is registered. This issue has been reported many times in past and people have been using workarounds like changing the pinctrl_amd to built-in instead of loading it as a module or by adding a softdep for pinctrl_amd into the config file. References :- https://bugzilla.kernel.org/show_bug.cgi?id=209413 https://github.com/Syniurge/i2c-amd-mp2/issues/3 Signed-off-by: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> --- Changes in v2 - Add a condition to check for irq chip to avoid bogus error. --- drivers/gpio/gpiolib.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 27c07108496d..12c088706167 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3084,6 +3084,14 @@ int gpiod_to_irq(const struct gpio_desc *desc) return retirq; } + if (gc->irq.chip) { + /* avoid race condition with other code, which tries to lookup + * an IRQ before the irqchip has been properly registered + * (i.e. while gpiochip is still being brought up). + */ + return -EPROBE_DEFER; + } + return -ENXIO; } EXPORT_SYMBOL_GPL(gpiod_to_irq); -- 2.30.2
