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| author | Marc Zyngier <maz@kernel.org> | 2020-12-04 16:47:36 +0000 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2020-12-09 10:23:04 +0100 |
| commit | a0db197f534fb24d64cc8c716b5f128f2de1c898 (patch) | |
| tree | 58e7c356f9718b56098f84176b2e804be24b3ba0 /drivers/gpio | |
| parent | 37ddba0245b4547621862c0b24bf36deb199bf5c (diff) | |
| download | linux-a0db197f534fb24d64cc8c716b5f128f2de1c898.tar.gz linux-a0db197f534fb24d64cc8c716b5f128f2de1c898.tar.bz2 linux-a0db197f534fb24d64cc8c716b5f128f2de1c898.zip | |
gpiolib: cdev: Flag invalid GPIOs as used
When reporting the state of a GPIO to userspace, we never check
for the actual validity of the line, meaning we report invalid
lines as being usable. A subsequent request will fail though,
which is an inconsistent behaviour from a userspace perspective.
Instead, let's check for the validity of the line and report it
as used if it is invalid. This allows a tool such as gpioinfo
to report something sensible:
gpiochip3 - 4 lines:
line 0: unnamed unused input active-high
line 1: unnamed kernel input active-high [used]
line 2: unnamed kernel input active-high [used]
line 3: unnamed unused input active-high
In this example, lines 1 and 2 are invalid, and cannot be used by
userspace.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201204164739.781812-2-maz@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib-cdev.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index f64a35767434..bd40d717765c 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -1914,6 +1914,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, test_bit(FLAG_USED_AS_IRQ, &desc->flags) || test_bit(FLAG_EXPORT, &desc->flags) || test_bit(FLAG_SYSFS, &desc->flags) || + !gpiochip_line_is_valid(gc, info->offset) || !ok_for_pinctrl) info->flags |= GPIO_V2_LINE_FLAG_USED; |