gpiolib: of: fix bounds check for 'gpio-reserved-ranges'
authorAndrei Lalaev <andrei.lalaev@emlid.com>
Fri, 15 Apr 2022 07:07:11 +0000 (10:07 +0300)
committerBartosz Golaszewski <brgl@bgdev.pl>
Mon, 2 May 2022 09:27:57 +0000 (11:27 +0200)
commite75f88efac05bf4e107e4171d8db6d8c3937252d
tree199d51036da259e029e89b961a9b2fad0661a7b0
parent672c0c5173427e6b3e2a9bbb7be51ceeec78093a
gpiolib: of: fix bounds check for 'gpio-reserved-ranges'

Gpiolib interprets the elements of "gpio-reserved-ranges" as "start,size"
because it clears "size" bits starting from the "start" bit in the according
bitmap. So it has to use "greater" instead of "greater or equal" when performs
bounds check to make sure that GPIOs are in the available range.
Previous implementation skipped ranges that include the last GPIO in
the range.

I wrote the mail to the maintainers
(https://lore.kernel.org/linux-gpio/20220412115554.159435-1-andrei.lalaev@emlid.com/T/#u)
of the questioned DTSes (because I couldn't understand how the maintainers
interpreted this property), but I haven't received a response.
Since the questioned DTSes use "gpio-reserved-ranges = <0 4>"
(i.e., the beginning of the range), this patch doesn't affect these DTSes at all.
TBH this patch doesn't break any existing DTSes because none of them
reserve gpios at the end of range.

Fixes: 726cb3ba4969 ("gpiolib: Support 'gpio-reserved-ranges' property")
Signed-off-by: Andrei Lalaev <andrei.lalaev@emlid.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
drivers/gpio/gpiolib-of.c