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gpiolib: Fix using uninitialized lookup-flags on ACPI platforms

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Commit 8eb1f71e7a ("gpiolib: consolidate GPIO lookups") refactors
fwnode_get_named_gpiod() and gpiod_get_index() into a unified
gpiod_find_and_request() helper.

The old functions both initialized their local lookupflags variable to
GPIO_LOOKUP_FLAGS_DEFAULT, but the new code leaves it uninitialized.

This is a problem for at least ACPI platforms, where acpi_find_gpio()
only does a bunch of *lookupflags |= GPIO_* statements and thus relies
on the variable being initialized.

The variable not being initialized leads to:

1. Potentially the wrong flags getting used
2. The check for conflicting lookup flags in gpiod_configure_flags():
   "multiple pull-up, pull-down or pull-disable enabled, invalid config"
   sometimes triggering, making the GPIO unavailable

Restore the initialization of lookupflags to GPIO_LOOKUP_FLAGS_DEFAULT
to fix this.

Fixes: 8eb1f71e7a ("gpiolib: consolidate GPIO lookups")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Hans de Goede 2022-12-29 17:45:01 +01:00 committed by Bartosz Golaszewski
parent 1b929c02af
commit ba2dc1cb54
1 changed files with 1 additions and 1 deletions
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2
drivers/gpio/gpiolib.c
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@ -3905,8 +3905,8 @@ static struct gpio_desc *gpiod_find_and_request(struct device *consumer,
const char *label,
bool platform_lookup_allowed)
{
unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
struct gpio_desc *desc = ERR_PTR(-ENOENT);
unsigned long lookupflags;
int ret;
if (!IS_ERR_OR_NULL(fwnode))