4.15-stable review patch. If anyone has any objections, please let me know.
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From: Bartosz Golaszewski brgl@bgdev.pl
[ Upstream commit 588fc3bceaf81bbd62e18af6f7bd475e01c2b7e8 ]
Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If the hardware actually supports enabling both at the same time the electrical result would be disastrous.
Suggested-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Bartosz Golaszewski brgl@bgdev.pl Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpio/gpiolib.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -460,6 +460,15 @@ static int linehandle_create(struct gpio if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) return -EINVAL;
+ /* + * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If + * the hardware actually supports enabling both at the same time the + * electrical result would be disastrous. + */ + if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && + (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) + return -EINVAL; + /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) && ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||