[Intel-gfx] [PATCH igt 3/4] tests/kms_fbc_crc: run even if FBC is disabled by default

[Paulo Zanoni]

2015-06-15 9:11 GMT-03:00 Daniel Vetter <daniel at ffwll.ch>:
> On Thu, Jun 04, 2015 at 11:31:05AM -0300, Paulo Zanoni wrote:
>> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>>
>> We may not be perfect, but if we don't even test, we will probably
>> only get worse over time.
>>
>> The function called makes sure we restore whatever was the original
>> FBC parameter when we exit the test, so this should not affect the
>> other tests.
>>
>> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
>> ---
>>  tests/kms_fbc_crc.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/tests/kms_fbc_crc.c b/tests/kms_fbc_crc.c
>> index 37221ac..d964224 100644
>> --- a/tests/kms_fbc_crc.c
>> +++ b/tests/kms_fbc_crc.c
>> @@ -559,10 +559,10 @@ igt_main
>>               igt_assert_lt(0, fread(buf, 1, sizeof(buf), status));
>>               fclose(status);
>>               buf[sizeof(buf) - 1] = '\0';
>> -             igt_require_f(!strstr(buf, "unsupported on this chipset") &&
>> -                           !strstr(buf, "disabled per module param") &&
>> -                           !strstr(buf, "disabled per chip default"),
>> -                           "FBC not supported/enabled\n");
>> +             igt_require_f(!strstr(buf, "unsupported on this chipset"),
>> +                           "FBC not supported\n");
>> +
>> +             igt_set_module_param_int("enable_fbc", 1);
>
> This is risky since on older chips fbc is known to pretty much insta-kill
> the box. Imo we should have a gen6+ here at least (that's roughly the
> point where the hw workarounds start to sound less scary).

Well, we can try and then keep an eye on bugzilla, watching for the
possible insta-kill bug reports, can't we? At least to me, this was
not known as instal-kill since it's not documented anywhere and we
don't have bug reports. Also, the move to the frontbuffer tracking
infrastructure could maybe have solved the insta-kill problem.

>
> Trying to enable this on older platforms just isn't worth it imo.

If we're not even going to try this, shouldn't we remove all the
Kernel code support for FBC on these platforms? This is something I
wanted to discuss at some point, but now you gave us a nice excuse :).
Maybe it's better to just not have the code at all vs have a code that
(maybe) instakills the machine and we're probably not going to fix
anytime soon. I don't know, just an idea.

Btw, those patches are already on IGT.  Thomas seemed to be OK with
the ideas, and after one week on the mailing list I pushed them.

> -Daniel
>
>
>>
>>               data.bufmgr = drm_intel_bufmgr_gem_init(data.drm_fd, 4096);
>>               igt_assert(data.bufmgr);
>> --
>> 2.1.4
>>
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>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch



-- 
Paulo Zanoni