Re: [PATCH v2] tests/intel: Avoid stale errno

["Anirban, Sk" <sk.anirban@intel.com>]

Hi,

On 07-09-2026 03:12 pm, Kamil Konieczny wrote:
> Hi Sk,
> On 2026-09-04 at 15:30:43 +0530, Sk Anirban wrote:
>> Commit <e311ed2c7> ("lib/igt_core: do not reset errno in igt_gettime")
>> removed an incidental errno reset that used to mask stale errno at
>> subtest entry. Now a stale errno from an earlier, unrelated probe can
>> survive into a later assertion failure and gets printed as a
>> misleading "Last errno" hint, e.g. in xe_gt_freq's throttle_basic_api:
>>
>>    CRITICAL: Failed assertion: !strcmp(throttle_reasons, "none")
>>    CRITICAL: Last errno: 2, No such file or directory
>>    CRITICAL: GT 0 is throttled due to: pl4
>>
>> The real cause is the GT being throttled; "Last errno: 2" is stale
>> and unrelated, making triage confusing.
>>
>> Fix this by clearing errno right where it is known to go stale.
>>
>> v2: Update fix path (Kamil)
>>
>> Signed-off-by: Sk Anirban <sk.anirban@intel.com>
> LGTM
> Reviewed-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>
>
> Regards,
> Kamil

Thanks for the review. Could you please merge the patch? I have already 
responded to the xe-ci-full failures.

Thanks,
Anirban

>> ---
>>   lib/xe/xe_gt.c                | 1 +
>>   tests/intel/xe_gt_freq.c      | 1 +
>>   tests/intel/xe_pm.c           | 1 +
>>   tests/intel/xe_pm_residency.c | 1 +
>>   tests/intel/xe_pmu.c          | 1 +
>>   5 files changed, 5 insertions(+)
>>
>> diff --git a/lib/xe/xe_gt.c b/lib/xe/xe_gt.c
>> index 8f54b6e25..3d8b4f68a 100644
>> --- a/lib/xe/xe_gt.c
>> +++ b/lib/xe/xe_gt.c
>> @@ -224,6 +224,7 @@ bool xe_gt_is_in_c6(int fd, int gt)
>>   		return true;
>>   
>>   	igt_debug("GT%d C-state is %s\n", gt, gt_c_state);
>> +	errno = 0;
>>   
>>   	return false;
>>   }
>> diff --git a/tests/intel/xe_gt_freq.c b/tests/intel/xe_gt_freq.c
>> index 19306dc41..886537862 100644
>> --- a/tests/intel/xe_gt_freq.c
>> +++ b/tests/intel/xe_gt_freq.c
>> @@ -397,6 +397,7 @@ int igt_main()
>>   			stash_min[gt] = xe_gt_get_freq(fd, gt, "min");
>>   			stash_max[gt] = xe_gt_get_freq(fd, gt, "max");
>>   		}
>> +		errno = 0;
>>   	}
>>   
>>   	igt_subtest("throttle_basic_api") {
>> diff --git a/tests/intel/xe_pm.c b/tests/intel/xe_pm.c
>> index 7faba7c2b..543f46f5b 100644
>> --- a/tests/intel/xe_pm.c
>> +++ b/tests/intel/xe_pm.c
>> @@ -990,6 +990,7 @@ int igt_main()
>>   
>>   		igt_install_exit_handler(igt_drm_debug_mask_reset_exit_handler);
>>   		update_debug_mask_if_ci(DRM_UT_KMS);
>> +		errno = 0;
>>   	}
>>   
>>   	for (const struct s_state *s = s_states; s->name; s++) {
>> diff --git a/tests/intel/xe_pm_residency.c b/tests/intel/xe_pm_residency.c
>> index bfae1f844..e976048a9 100644
>> --- a/tests/intel/xe_pm_residency.c
>> +++ b/tests/intel/xe_pm_residency.c
>> @@ -574,6 +574,7 @@ int igt_main()
>>   
>>   		igt_require(!IS_PONTEVECCHIO(xe_dev_id(fd)));
>>   		igt_require(xe_sysfs_gt_has_node(fd, 0, "gtidle"));
>> +		errno = 0;
>>   	}
>>   
>>   	igt_describe("Validate GT C6 on idle");
>> diff --git a/tests/intel/xe_pmu.c b/tests/intel/xe_pmu.c
>> index a8ceac46c..5b098c45c 100644
>> --- a/tests/intel/xe_pmu.c
>> +++ b/tests/intel/xe_pmu.c
>> @@ -1076,6 +1076,7 @@ int igt_main()
>>   		xe_perf_device(fd, xe_device, sizeof(xe_device));
>>   		num_engines = xe_number_engines(fd);
>>   		has_engine_active_ticks = has_event(xe_device, "engine-active-ticks");
>> +		errno = 0;
>>   	}
>>   
>>   	igt_describe("Validate PMU gt-c6 residency counters when idle");
>> -- 
>> 2.43.0
>>