Re: [PATCH i-g-t] tests/intel/xe_oa: Call get_stream_status only on EIO

[Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>]

On Wed, Apr 16, 2025 at 04:16:40PM -0700, Dixit, Ashutosh wrote:
>On Wed, 16 Apr 2025 16:12:02 -0700, Umesh Nerlige Ramappa wrote:
>>
>> Turns out that get_stream_status resets errno and anything that checks
>> errno afterwards fails. This resulted in a bunch of test failures. Fix
>> it by calling get_stream_status only if errno is EIO and also save and
>> restore errno within get_stream_status.
>>
>> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/issues/4804
>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
>> ---
>>  tests/intel/xe_oa.c | 20 ++++++++++++++------
>>  1 file changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/tests/intel/xe_oa.c b/tests/intel/xe_oa.c
>> index 1fc8bfaafee2..360dd8ba00d9 100644
>> --- a/tests/intel/xe_oa.c
>> +++ b/tests/intel/xe_oa.c
>> @@ -380,9 +380,11 @@ static void set_fd_flags(int fd, int flags)
>>  static u32 get_stream_status(int fd)
>>  {
>>	struct drm_xe_oa_stream_status status;
>> +	int _e = errno;
>>
>>	do_ioctl(fd, DRM_XE_OBSERVATION_IOCTL_STATUS, &status);
>>	igt_debug("oa status %llx\n", status.oa_status);
>> +	errno = _e;
>>
>>	return status.oa_status;
>>  }
>> @@ -2294,7 +2296,8 @@ static void test_polling_small_buf(void)
>>	errno = 0;
>>	ret = read(stream_fd, buf, sizeof(buf));
>>	igt_assert_eq(ret, -1);
>> -	get_stream_status(stream_fd);
>> +	if (errno == EIO)
>> +		get_stream_status(stream_fd);
>
>Hi Umesh, if we are saving/restoring errno in get_stream_status(), do we
>still need to check for EIO? Or you just want to check for EIO anyhow?

I wanted to make sure of both actually. Ideally, we get the stream 
status only on EIO. In future if anyone does not follow that and just 
calls the get_stream_status, then preserve the errno to avoid strange 
issues. Maybe should update the commit then?

Thanks,
Umesh
>
>Thanks.
>--
>Ashutosh