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authorShiji Yang <yangshiji66@outlook.com>2024-06-25 03:19:49 +0200
committerBartosz Golaszewski <bartosz.golaszewski@linaro.org>2024-07-03 15:27:59 +0200
commitf07798d7bb9c46d17d80103fb772fd2c75d47919 (patch)
tree308fe5f604b00d6d7e1986ae433d329d26807adb /drivers/gpio
parentgpiolib: of: fix lookup quirk for MIPS Lantiq (diff)
downloadlinux-f07798d7bb9c46d17d80103fb772fd2c75d47919.tar.xz
linux-f07798d7bb9c46d17d80103fb772fd2c75d47919.zip
gpio: mmio: do not calculate bgpio_bits via "ngpios"
bgpio_bits must be aligned with the data bus width. For example, on a 32 bit big endian system and we only have 16 GPIOs. If we only assume bgpio_bits=16 we can never control the GPIO because the base address is the lowest address. low address high address ------------------------------------------------- | byte3 | byte2 | byte1 | byte0 | ------------------------------------------------- | NaN | NaN | gpio8-15 | gpio0-7 | ------------------------------------------------- Fixes: 55b2395e4e92 ("gpio: mmio: handle "ngpios" properly in bgpio_init()") Fixes: https://github.com/openwrt/openwrt/issues/15739 Reported-by: Mark Mentovai <mark@mentovai.com> Signed-off-by: Shiji Yang <yangshiji66@outlook.com> Suggested-By: Mark Mentovai <mark@mentovai.com> Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com> Tested-by: Lóránd Horváth <lorand.horvath82@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/TYCP286MB089577B47D70F0AB25ABA6F5BCD52@TYCP286MB0895.JPNP286.PROD.OUTLOOK.COM Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpio-mmio.c2
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/gpio/gpio-mmio.c b/drivers/gpio/gpio-mmio.c
index 71e1af7c2184..d89e78f0ead3 100644
--- a/drivers/gpio/gpio-mmio.c
+++ b/drivers/gpio/gpio-mmio.c
@@ -619,8 +619,6 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
ret = gpiochip_get_ngpios(gc, dev);
if (ret)
gc->ngpio = gc->bgpio_bits;
- else
- gc->bgpio_bits = roundup_pow_of_two(round_up(gc->ngpio, 8));
ret = bgpio_setup_io(gc, dat, set, clr, flags);
if (ret)