diff options
| author | Maxime Ripard <mripard@kernel.org> | 2023-07-28 11:06:24 +0200 |
|---|---|---|
| committer | Maxime Ripard <mripard@kernel.org> | 2023-07-31 14:19:58 +0200 |
| commit | b229ea58cbe2f107dc0a7e2c7cdce193f7166b47 (patch) | |
| tree | bfc98102354b638c7a0382f936b8766b210a64f8 /drivers/gpu/drm/vc4 | |
| parent | 1ef726c8fbd6a970fe0e752d68bb051954d77461 (diff) | |
drm/vc4: tests: pv-muxing: Document test scenario
We've had a couple of tests that weren't really obvious, nor did they
document what they were supposed to test. Document that to make it
hopefully more obvious.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maíra Canal <mairacanal@riseup.net>
Link: https://lore.kernel.org/r/20230728-kms-kunit-actions-rework-v3-11-952565ccccfe@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Diffstat (limited to 'drivers/gpu/drm/vc4')
| -rw-r--r-- | drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c b/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c index 5f9f5626329d..61622e951031 100644 --- a/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c +++ b/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c @@ -845,6 +845,13 @@ static void drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable(struct kunit *tes KUNIT_EXPECT_NE(test, hdmi0_channel, hdmi1_channel); } +/* + * This test makes sure that we never change the FIFO of an active HVS + * channel if we disable a FIFO with a lower index. + * + * Doing so would result in a FIFO stall and would disrupt an output + * supposed to be unaffected by the commit. + */ static void drm_test_vc5_pv_muxing_bugs_stable_fifo(struct kunit *test) { struct drm_modeset_acquire_ctx *ctx; @@ -924,6 +931,21 @@ static void drm_test_vc5_pv_muxing_bugs_stable_fifo(struct kunit *test) } } +/* + * Test that if we affect a single output, only the CRTC state of that + * output will be pulled in the global atomic state. + * + * This is relevant for two things: + * + * - If we don't have that state at all, we are unlikely to affect the + * FIFO muxing. This is somewhat redundant with + * drm_test_vc5_pv_muxing_bugs_stable_fifo() + * + * - KMS waits for page flips to occur on all the CRTC found in the + * CRTC state. Since the CRTC is unaffected, we would over-wait, but + * most importantly run into corner cases like waiting on an + * inactive CRTC that never completes. + */ static void drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable_too_many_crtc_state(struct kunit *test) { |