Re: [PATCH] gpiolib-acpi: make sure we trigger edge events at least once on boot

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Wed, 2018-07-11 at 22:23 +0200, Hans de Goede wrote:

> Note that the running of the event-handler is done 3 seconds after the
> GPIO driver loads, this is done because the event-handler AML code may
> rely on OperationRegions registered by other drivers and the GPIO
> driver
> is initialized very early on, where as the total init of all drivers
> can
> take up to 2.5 seconds. This delay avoid errors like these:
> 
> [    0.133026] ACPI Error: No handler for Region [XSCG]
> ((____ptrval____)) [GenericSerialBus] (20180531/evregion-132)
> [    0.133036] ACPI Error: Region GenericSerialBus (ID=9) has no
> handler (20180531/exfldio-265)
> [    0.133046] ACPI Error: Method parse/execution failed
> \_SB.GPO2._E12, AE_NOT_EXIST (20180531/psparse-516)

 
> +/* Initialization of all builtin drivers may take up to 2.5 seconds
> */

Ouch, this sounds quite fragile. On your case it's 2.5s, on someone's
else it might take 5 or more?

Maybe we could go other way around, i.e. if the driver in question needs
to be loaded and requires this W/A, it can notify somehow GPIO ACPI to
sync the state?

-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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