From: Ivo Borisov Shopov <ivoshopov@xxxxxxxxx>
[ 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@xxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
[Bartosz: tweak the commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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;
--
2.39.0
