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authorBartosz Golaszewski <bgolaszewski@baylibre.com>2019-08-06 13:41:51 +0200
committerLinus Walleij <linus.walleij@linaro.org>2019-08-14 10:57:18 +0200
commit2c60e6b5c9241b24b8b523fefd3e44fb85622cda (patch)
treee0e98cde759d582b45ebd0f331edcf46eda3a1e4 /drivers/gpio
parentd45331b00ddb179e291766617259261c112db872 (diff)
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gpiolib: never report open-drain/source lines as 'input' to user-space
If the driver doesn't support open-drain/source config options, we emulate this behavior when setting the direction by calling gpiod_direction_input() if the default value is 0 (open-source) or 1 (open-drain), thus not actively driving the line in those cases. This however clears the FLAG_IS_OUT bit for the GPIO line descriptor and makes the LINEINFO ioctl() incorrectly report this line's mode as 'input' to user-space. This commit modifies the ioctl() to always set the GPIOLINE_FLAG_IS_OUT bit in the lineinfo structure's flags field. Since it's impossible to use the input mode and open-drain/source options at the same time, we can be sure the reported information will be correct. Fixes: 521a2ad6f862 ("gpio: add userspace ABI for GPIO line information") Cc: stable <stable@vger.kernel.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Link: https://lore.kernel.org/r/20190806114151.17652-1-brgl@bgdev.pl Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f497003f119c..80a2a2cb673b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1091,9 +1091,11 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
- lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
+ lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
+ GPIOLINE_FLAG_IS_OUT);
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
- lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
+ lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
+ GPIOLINE_FLAG_IS_OUT);
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;