This is a note to let you know that I've just added the patch titled

gpiolib: don't allow OPEN_DRAIN & OPEN_SOURCE flags simultaneously

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: gpiolib-don-t-allow-open_drain-open_source-flags-simultaneously.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Fri Mar 16 15:11:07 CET 2018

From: Bartosz Golaszewski brgl@bgdev.pl Date: Wed, 15 Nov 2017 16:47:43 +0100 Subject: gpiolib: don't allow OPEN_DRAIN & OPEN_SOURCE flags simultaneously

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) ||

Patches currently in stable-queue which might be from brgl@bgdev.pl are

queue-4.15/gpiolib-don-t-allow-open_drain-open_source-flags-simultaneously.patch