From: Christophe Leroy (CS GROUP) Date: Wed, 29 Jul 2026 09:47:20 +0000 (+0200) Subject: gpiolib: Check gc->get_direction() before calling gpiod_get_direction() X-Git-Tag: v7.2~29^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d761c7e38a000603a9d16270a1af770a0e8efb5e;p=thirdparty%2Fkernel%2Flinux.git gpiolib: Check gc->get_direction() before calling gpiod_get_direction() According to 'struct gpio_chip' documentation in linux/gpio/driver.h, implementing .get_direction() is recommended but not mandatory. Most places verify that gc->get_direction() exists before calling gpiod_get_direction(), but gpiolib_dbg_show() doesn't. Until commit 471e998c0e31 ("gpiolib: remove redundant callback check") it was also verified by gpiod_get_direction() itself so calling it at all time from gpiolib_dbg_show() was not an issue. But after the check in gpiod_get_direction() has been removed, calling it inconditionaly leads to a big fat warning in gpiochip_get_direction(). In gpiod_get_direction(), verify that gc->get_direction() exists before calling gpiod_get_direction(). Fixes: 471e998c0e31 ("gpiolib: remove redundant callback check") Signed-off-by: Christophe Leroy (CS GROUP) Link: https://patch.msgid.link/ad89f92f91d004e63dd5599bb58e9581f373a601.1785318183.git.chleroy@kernel.org Signed-off-by: Bartosz Golaszewski --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index c433a095907f..ef8ccaf17c9c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -5420,7 +5420,8 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *gc) flags = READ_ONCE(desc->flags); is_irq = test_bit(GPIOD_FLAG_USED_AS_IRQ, &flags); if (is_irq || test_bit(GPIOD_FLAG_REQUESTED, &flags)) { - gpiod_get_direction(desc); + if (gc->get_direction) + gpiod_get_direction(desc); is_out = test_bit(GPIOD_FLAG_IS_OUT, &flags); value = gpio_chip_get_value(gc, desc); active_low = test_bit(GPIOD_FLAG_ACTIVE_LOW, &flags);