| Message ID | 20171115154743.5921-1-brgl@bgdev.pl |
|---|---|
| State | New |
| Headers | show |
| Series | gpiolib: don't allow OPEN_DRAIN & OPEN_SOURCE flags simultaneously | expand |
On Wed, Nov 15, 2017 at 4:47 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote: > 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> > --- > There was a misunderstanding as to what the goal of my previous commit > 609aaf6a6029 ("gpiolib: don't allow OPEN_DRAIN & OPEN_SOURCE flags for > input") was, which resulted in discovering another thing that needs > fixing. This change was suggested to me by Linus earlier today. Awesome, thanks. Patch applied. I wonder if we should even put some swear words into dmesg for this. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 641a5eb552cb..ec80e0146fd5 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -459,6 +459,15 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) 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) ||
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> --- There was a misunderstanding as to what the goal of my previous commit 609aaf6a6029 ("gpiolib: don't allow OPEN_DRAIN & OPEN_SOURCE flags for input") was, which resulted in discovering another thing that needs fixing. This change was suggested to me by Linus earlier today. drivers/gpio/gpiolib.c | 9 +++++++++ 1 file changed, 9 insertions(+)