Re: [PATCH] gpio / ACPI: Return -EPROBE_DEFER if the gpiochip was not found

[Tobias Diedrich <ranma+kernel@xxxxxxxxxxxx>]

Rafael J. Wysocki wrote:
> On Wednesday, June 10, 2015 04:05:05 PM Mika Westerberg wrote:
> > If a driver requests a GPIO described in its _CRS but the GPIO host
> > controller (gpiochip) driver providing the GPIO has not been loaded yet
> > acpi_get_gpiod() returns -ENODEV which causes the calling driver to fail.
> > 
> > If the gpiochip driver is loaded afterwards the driver requesting the GPIO
> > will not notice this.
> > 
> > Better approach is to return -EPROBE_DEFER in such case. Then when the
> > gpiochip driver appears the driver requesting the GPIO will be probed
> > again. This also aligns ACPI GPIO lookup code closer to DT as it does
> > pretty much the same when no gpiochip driver was found.
> > 
> > Reported-by: Tobias Diedrich <tobiasdiedrich@xxxxxxxxx>
> > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> 
> Makes sense to me.
> 
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Signed-off-by: Tobias Diedrich <ranma+kernel@xxxxxxxxxxxx>

-- 
Tobias						PGP: http://8ef7ddba.uguu.de
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