diff mbox

gpiolib: fix filtering out unwanted events

Message ID 1498218316-27860-2-git-send-email-brgl@bgdev.pl
State New
Headers show

Commit Message

Bartosz Golaszewski June 23, 2017, 11:45 a.m. UTC
GPIOEVENT_REQUEST_BOTH_EDGES is not a single flag, but a binary OR of
GPIOEVENT_REQUEST_RISING_EDGE and GPIOEVENT_REQUEST_FALLING_EDGE.

The expression 'le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES' we'll get
evaluated to true even if only one event type was requested.

Fix it by checking both RISING & FALLING flags explicitly.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
 drivers/gpio/gpiolib.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Linus Walleij June 29, 2017, 9:33 a.m. UTC | #1
On Fri, Jun 23, 2017 at 1:45 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> GPIOEVENT_REQUEST_BOTH_EDGES is not a single flag, but a binary OR of
> GPIOEVENT_REQUEST_RISING_EDGE and GPIOEVENT_REQUEST_FALLING_EDGE.
>
> The expression 'le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES' we'll get
> evaluated to true even if only one event type was requested.
>
> Fix it by checking both RISING & FALLING flags explicitly.
>
> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Patch applied for fixes.

Yours,
Linus Walleij
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Bartosz Golaszewski June 29, 2017, 11:03 a.m. UTC | #2
2017-06-29 11:33 GMT+02:00 Linus Walleij <linus.walleij@linaro.org>:
> On Fri, Jun 23, 2017 at 1:45 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>
>> GPIOEVENT_REQUEST_BOTH_EDGES is not a single flag, but a binary OR of
>> GPIOEVENT_REQUEST_RISING_EDGE and GPIOEVENT_REQUEST_FALLING_EDGE.
>>
>> The expression 'le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES' we'll get
>> evaluated to true even if only one event type was requested.
>>
>> Fix it by checking both RISING & FALLING flags explicitly.
>>
>> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
>
> Patch applied for fixes.
>
> Yours,
> Linus Walleij

Thanks. I think this should also go to linux-stable (e.g. 4.9 LTS is
affected). Will you forward it or should I do it myself?

Thanks,
Bartosz
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Linus Walleij June 29, 2017, 1:16 p.m. UTC | #3
On Thu, Jun 29, 2017 at 1:03 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> 2017-06-29 11:33 GMT+02:00 Linus Walleij <linus.walleij@linaro.org>:
>> On Fri, Jun 23, 2017 at 1:45 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>>
>>> GPIOEVENT_REQUEST_BOTH_EDGES is not a single flag, but a binary OR of
>>> GPIOEVENT_REQUEST_RISING_EDGE and GPIOEVENT_REQUEST_FALLING_EDGE.
>>>
>>> The expression 'le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES' we'll get
>>> evaluated to true even if only one event type was requested.
>>>
>>> Fix it by checking both RISING & FALLING flags explicitly.
>>>
>>> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
>>
>> Patch applied for fixes.
>>
>> Yours,
>> Linus Walleij
>
> Thanks. I think this should also go to linux-stable (e.g. 4.9 LTS is
> affected). Will you forward it or should I do it myself?

I have added the stable tag so it should JustWork(TM).

Yours,
Linus Walleij
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diff mbox

Patch

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5db4413..a42a1ee 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -708,7 +708,8 @@  static irqreturn_t lineevent_irq_thread(int irq, void *p)
 
 	ge.timestamp = ktime_get_real_ns();
 
-	if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
+	if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
+	    && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
 		int level = gpiod_get_value_cansleep(le->desc);
 
 		if (level)