| Message ID | 20211116093833.245542-1-shreeya.patel@collabora.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4] gpio: Return EPROBE_DEFER if gc->to_irq is NULL | expand |
Shreeya Patel <shreeya.patel@collabora.com> writes: > 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. > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209413 > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com> Hi guys, This seems to not have reached the Linus tree on 5.17. If I'm not mistaken, it also hasn't reached linux-next as of today. Is there anything I'm missing here? This is required to prevent spurious probe crashes of devices like this FocalTech touchscreen, FT3528, when using pinctrl-amd. We've been carrying it downstream for quite a while. Thanks,
On Thu, Feb 10, 2022 at 5:36 PM Gabriel Krisman Bertazi <krisman@collabora.com> wrote: > > Shreeya Patel <shreeya.patel@collabora.com> writes: > > > 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. > > > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209413 > > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > Reported-by: kernel test robot <lkp@intel.com> > > Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com> > > Hi guys, > > This seems to not have reached the Linus tree on 5.17. If I'm not > mistaken, it also hasn't reached linux-next as of today. Is there > anything I'm missing here? > > This is required to prevent spurious probe crashes of devices like this > FocalTech touchscreen, FT3528, when using pinctrl-amd. We've been > carrying it downstream for quite a while. > > Thanks, > > -- > Gabriel Krisman Bertazi Hi Gabriel! My email address changed in September, that's why I didn't see the email you sent in November to my old one. gpiod_to_irq() can be used in context other than driver probing, I'm worried existing users would not know how to handle it. Also: how come you can get the GPIO descriptor from the provider but its interrupts are not yet set up? Bart
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index abfbf546d159..7b3f7f4d1d06 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3111,6 +3111,16 @@ int gpiod_to_irq(const struct gpio_desc *desc) return retirq; } +#ifdef CONFIG_GPIOLIB_IRQCHIP + 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; + } +#endif return -ENXIO; } EXPORT_SYMBOL_GPL(gpiod_to_irq);