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;a=summary
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@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Mar 16 15:11:07 CET 2018
From: Bartosz Golaszewski <brgl@xxxxxxxx>
Date: Wed, 15 Nov 2017 16:47:43 +0100
Subject: gpiolib: don't allow OPEN_DRAIN & OPEN_SOURCE flags simultaneously
From: Bartosz Golaszewski <brgl@xxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxx are
queue-4.15/gpiolib-don-t-allow-open_drain-open_source-flags-simultaneously.patch