From: Ivo Borisov Shopov ivoshopov@gmail.com
[ Upstream commit 677d85e1a1ee69fa05ccea83847309484be3781c ]
Following line should listen for a rising edge and exit after the first one since '-c 1' is provided.
# gpio-event-mon -n gpiochip1 -o 0 -r -c 1
It works with kernel 4.19 but it doesn't work with 5.10. In 5.10 the above command doesn't exit after the first rising edge it keep listening for an event forever. The '-c 1' is not taken into an account. The problem is in commit 62757c32d5db ("tools: gpio: add multi-line monitoring to gpio-event-mon"). Before this commit the iterator 'i' in monitor_device() is used for counting of the events (loops). In the case of the above command (-c 1) we should start from 0 and increment 'i' only ones and hit the 'break' statement and exit the process. But after the above commit counting doesn't start from 0, it start from 1 when we listen on one line. It is because 'i' is used from one more purpose, counting of lines (num_lines) and it isn't restore to 0 after following code
for (i = 0; i < num_lines; i++) gpiotools_set_bit(&values.mask, i);
Restore the initial value of the iterator to 0 in order to allow counting of loops to work for any cases.
Fixes: 62757c32d5db ("tools: gpio: add multi-line monitoring to gpio-event-mon") Signed-off-by: Ivo Borisov Shopov ivoshopov@gmail.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com [Bartosz: tweak the commit message] Signed-off-by: Bartosz Golaszewski bartosz.golaszewski@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/gpio/gpio-event-mon.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/gpio/gpio-event-mon.c b/tools/gpio/gpio-event-mon.c index 84ae1039b0a8..367c10636890 100644 --- a/tools/gpio/gpio-event-mon.c +++ b/tools/gpio/gpio-event-mon.c @@ -86,6 +86,7 @@ int monitor_device(const char *device_name, gpiotools_test_bit(values.bits, i)); }
+ i = 0; while (1) { struct gpio_v2_line_event event;