On Tue, Oct 19, 2021 at 1:07 AM Shreeya Patel
[off-list ref] wrote:

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

Please, convert them to BugLink: tags.

Signed-off-by: Shreeya Patel <redacted>

...

+       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).
+                */

/*
 * The style of multi-line comments should be
 * like this. Pay attention to the grammar.
 * In your comment the parentheses can be replaced
 * by a simple ',' (comma without quotes).
 */

+               return -EPROBE_DEFER;
+       }

With above (including kbuildbot thingy) addressed
Reviewed-by: Andy Shevchenko <redacted>

-- 
With Best Regards,
Andy Shevchenko