[igt-dev] [v3] tests/kms_color: Fix CRC mismatch issues with ctm test

[Shankar, Uma]

>On Wed, Mar 27, 2019 at 06:20:10AM +0000, Shankar, Uma wrote:
>>
>>
>> >-----Original Message-----
>> >From: Ville Syrjälä [mailto:ville.syrjala at linux.intel.com]
>> >Sent: Tuesday, March 26, 2019 10:16 PM
>> >To: Shankar, Uma <uma.shankar at intel.com>
>> >Cc: igt-dev at lists.freedesktop.org; Syrjala, Ville
>> ><ville.syrjala at intel.com>; Lankhorst, Maarten
>> ><maarten.lankhorst at intel.com>
>> >Subject: Re: [igt-dev] [v3] tests/kms_color: Fix CRC mismatch issues
>> >with ctm test
>> >
>> >On Tue, Mar 26, 2019 at 10:31:01AM +0000, Shankar, Uma wrote:
>> >>
>> >>
>> >> >-----Original Message-----
>> >> >From: Shankar, Uma
>> >> >Sent: Monday, March 25, 2019 2:11 PM
>> >> >To: igt-dev at lists.freedesktop.org
>> >> >Cc: Shankar, Uma <uma.shankar at intel.com>
>> >> >Subject: [v3] tests/kms_color: Fix CRC mismatch issues with ctm
>> >> >test
>> >> >
>> >> >Due to Gamma/Degamma limitation with precision (lack of exact 1.0
>> >> >representation) due to ABI restriction, applying linear gamma
>> >> >affects crc. This patch fixes the same by making ctm tests
>> >> >independant of
>> >gamma/degamma.
>> >> >
>> >> >v2: Disable degamma/gamma programming for ctm max test as it leads
>> >> >to crc mimsmatch. Limiting it to this test case alone as other
>> >> >tests need it to be enabled, hence not touching those scenarios.
>> >> >
>> >> >v3: Fixed a fumble with compilation.
>> >>
>> >> Hi Ville,
>> >> Can I keep your RB on this version. We have a clean CI result available now.
>> >
>> >I'm confused. Why didn't disabling degamma+gamma work?
>>
>> We need to disable degamma/gamma and also make sure we don't set them
>> again with linear values, which was being done currently. Hence,
>> disabled it and later made sure it's kept at that.
>
>Who is turning it back on and why?

When we call disable from IGT, it passes a NULL LUT. In this case, default linear LUT is
getting applied in kernel. I am not sure if we really disable the gamma/degamma fully in
driver. It just works with linear values and remains enabled.

>>
>> Regards,
>> Uma Shankar
>>
>> >>
>> >> Thanks & Regards,
>> >> Uma Shankar
>> >>
>> >> >Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108147
>> >> >Signed-off-by: Uma Shankar <uma.shankar at intel.com>
>> >> >---
>> >> > tests/kms_color.c | 16 ++++++++++++++--
>> >> > 1 file changed, 14 insertions(+), 2 deletions(-)
>> >> >
>> >> >diff --git a/tests/kms_color.c b/tests/kms_color.c index
>> >> >decf3c2..dcc86ad 100644
>> >> >--- a/tests/kms_color.c
>> >> >+++ b/tests/kms_color.c
>> >> >@@ -696,8 +696,15 @@ static bool test_pipe_ctm(data_t *data,
>> >> > 		igt_assert(fb_modeset_id);
>> >> > 		igt_plane_set_fb(primary, &fb_modeset);
>> >> >
>> >> >-		set_degamma(data, primary->pipe, degamma_linear);
>> >> >-		set_gamma(data, primary->pipe, gamma_linear);
>> >> >+		/*
>> >> >+		 * Don't program LUT's for max CTM cases as limitation of
>> >> >+		 * representing 1.0 due to ABI limits causes crc mismatch
>> >> >+		 */
>> >> >+		if (memcmp(before, after, sizeof(color_t))) {
>> >> >+			set_degamma(data, primary->pipe, degamma_linear);
>> >> >+			set_gamma(data, primary->pipe, gamma_linear);
>> >> >+		}
>> >> >+
>> >> > 		disable_ctm(primary->pipe);
>> >> > 		igt_display_commit(&data->display);
>> >> >
>> >> >@@ -1005,6 +1012,11 @@ run_tests_for_pipe(data_t *data, enum pipe p)
>> >> > 		 * produce with an 8 bits per color framebuffer. */
>> >> > 		igt_require(!IS_CHERRYVIEW(data->devid));
>> >> >
>> >> >+		/* Disable and let default luts be applied by kernel */
>> >> >+		disable_degamma(primary->pipe);
>> >> >+		disable_gamma(primary->pipe);
>> >> >+		igt_display_commit(&data->display);
>> >> >+
>> >> > 		igt_assert(test_pipe_ctm(data, primary, red_green_blue,
>> >> > 					 full_rgb, ctm));
>> >> > 	}
>> >> >--
>> >> >1.9.1
>> >>
>> >> _______________________________________________
>> >> igt-dev mailing list
>> >> igt-dev at lists.freedesktop.org
>> >> https://lists.freedesktop.org/mailman/listinfo/igt-dev
>> >
>> >--
>> >Ville Syrjälä
>> >Intel
>
>--
>Ville Syrjälä
>Intel