[LTP] [PATCH v2] input_common.h: Add retry loop for event device

[Edward Liaw]

On Mon, Mar 3, 2025 at 1:35 AM Li Wang <liwang@redhat.com> wrote:

>
>
> On Sat, Mar 1, 2025 at 2:49 AM Edward Liaw via ltp <ltp@lists.linux.it>
> wrote:
>
>> Android has a delay between the entry in /proc/bus/input/devices and the
>> path /dev/input/eventN becoming accessible.  Add a retry loop to account
>> for this.
>>
>
> Did you count for how long it takes to entry? The default time
> TST_RETRY_FUNC
> is backoff 1 second, if that time is not enough, you can consider the
> completed
> version TST_RETRY_FN_EXP_BACKOFF for setting more seconds.
>
> Anyway, this looks good.
> Reviewed-by: Li Wang <liwang@redhat.com>
>

Yeah, 1 sec should be more than enough for Android; the delay has so far
been on the order of microseconds.

>
>
>
>>
>> Signed-off-by: Edward Liaw <edliaw@google.com>
>> ---
>>  testcases/kernel/input/input_common.h | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/testcases/kernel/input/input_common.h
>> b/testcases/kernel/input/input_common.h
>> index 0ac1624b3..5b1755771 100644
>> --- a/testcases/kernel/input/input_common.h
>> +++ b/testcases/kernel/input/input_common.h
>> @@ -29,7 +29,7 @@ static inline int open_event_device(void)
>>                         memset(path, 0, sizeof(path));
>>                         snprintf(path, sizeof(path), "/dev/input/%s",
>> device);
>>
>> -                       if (!access(path, F_OK)) {
>> +                       if (!TST_RETRY_FUNC(access(path, F_OK),
>> TST_RETVAL_EQ0)) {
>>                                 tst_res(TINFO, "Found event device: %s",
>> path);
>>                                 break;
>>                         }
>> --
>> 2.48.1.711.g2feabab25a-goog
>>
>>
>> --
>> Mailing list info: https://lists.linux.it/listinfo/ltp
>>
>>
>
> --
> Regards,
> Li Wang
>