[Intel-gfx] [PATCH] drm/i915/selftests: Log test and subtest names for easier debugging

[Tvrtko Ursulin]

On 20/11/2018 18:10, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2018-11-20 17:58:33)
>>
>> On 20/11/2018 17:33, Chris Wilson wrote:
>>> Quoting Tvrtko Ursulin (2018-11-20 17:28:39)
>>>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>>>
>>>> Since pr_debug is not printed by default, change both test and subtest
>>>> log messages to pr_info so they are always logged.
>>>
>>> I just use the trace... As when the test fails we say which subtest
>>> failed, and hopefully include more details in the error message, and
>>> recent history is in the trace dumped when considered relevant.
>>
>> Fair. My thinking was simply to leave more breadcrumbs if the machine
>> died in the middle of a subtest.
> 
> Thinking more about it, the easiest option would be to actually enable
> pr_debug, iirc a config option.

AFAICT we would need to pass -DDEBUG to interesting compilation units.

> However, the only time we don't get breadcrumbs is if the machine
> spontaneously combusts, which we are told is a mere figment of our
> imagination.  Most often I wonder if we simply do not get the death
> throes - adding logging won't help if we don't capture it. For the true
> spontaneous combustion, it's pretty random and all I can think of
> suggesting are more sanity checks to try and catch inconsistencies early.

Well I was looking at one such log today so hence the patch.. :)

<6>[  491.437102] i915: Performing live selftests with st_random_seed=0x3bd88daf st_timeout=1000
<7>[  491.438062] [drm:intel_power_well_enable [i915]] enabling always-on
<7>[  491.438121] [drm:intel_power_well_enable [i915]] enabling DC off
<7>[  491.438509] [drm:gen9_set_dc_state [i915]] Setting DC state from 02 to 00
<7>[  491.541663] [drm:intel_power_well_disable [i915]] disabling DC off
<7>[  491.541722] [drm:skl_enable_dc6 [i915]] Enabling DC6
<7>[  491.541751] [drm:gen9_set_dc_state [i915]] Setting DC state from 00 to 02
<7>[  491.542180] [drm:intel_power_well_disable [i915]] disabling always-on
<7>[  495.443505] [drm:intel_power_well_enable [i915]] enabling always-on
<7>[  495.443533] [drm:intel_power_well_enable [i915]] enabling DC off
<7>[  495.443817] [drm:gen9_set_dc_state [i915]] Setting DC state from 02 to 00
<7>[  499.549369] [drm:intel_power_well_disable [i915]] disabling DC off
<7>[  499.549403] [drm:skl_enable_dc6 [i915]] Enabling DC6
<7>[  499.549431] [drm:gen9_set_dc_state [i915]] Setting DC state from 00 to 02
<7>[  499.549863] [drm:intel_power_well_disable [i915]] disabling always-on
<6>[  500.448268] i915_reset_engine(rcs0:idle): 265564 resets
<6>[  501.449250] i915_reset_engine(bcs0:idle): 249487 resets
EOF

I can certainly send a patch for -DDEBUG, seems like that would be the
correct thing to do for all selftests.

Regards,

Tvrtko