| Message ID | 20240919-exynosdrm-decon-v1-2-6c5861c1cb04@disroot.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Samsung Exynos 7870 DECON driver support | expand |
On 19/09/2024 17:11, Kaustabh Chakraborty wrote: > decon_commit() gets called during atomic_enable. At this stage, DECON is > suspended, and thus the function refuses to run. Fix the suspended > condition checking in decon_commit(). > > Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org> > --- If this is a fix, then you miss fixes tag and cc-stable. However the explanation seems just incomplete. This looked like a intentional code, so you should explain really why original approach was wrong. Best regards, Krzysztof
On 2024-09-20 12:40, Krzysztof Kozlowski wrote: > On 19/09/2024 17:11, Kaustabh Chakraborty wrote: >> decon_commit() gets called during atomic_enable. At this stage, DECON is >> suspended, and thus the function refuses to run. Fix the suspended >> condition checking in decon_commit(). >> >> Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org> >> --- > > If this is a fix, then you miss fixes tag and cc-stable. However the > explanation seems just incomplete. This looked like a intentional code, > so you should explain really why original approach was wrong. Fixes: 96976c3d9aff ("drm/exynos: Add DECON driver") Now that I read the commit description of the above commit, which mentions that the DECON driver is based on the FIMD driver, I think it makes more sense to rewrite the suspend logic exactly as done in the FIMD driver. Will do it in v2. Here's a commit description which may be better suited, let me know: A flag variable in struct decon_context, called 'suspended' is set to false at the end of decon_atomic_enable() and is set back to true at the end of decon_atomic_disable(). Functions called in decon_atomic_enable(), such as decon_enable_vblank() and decon_commit() are guarded by suspend condition checking, where it refuses to proceed if 'suspended' is set to true. Since 'suspended' isn't set to true until the end of the calling function, the called functions aren't even executed. The original commit, 96976c3d9aff ("drm/exynos: Add DECON driver") implementing the DECON driver, is based on the FIMD driver, but changes the suspend flag logic which causes this issue. Implement the suspend logic present in FIMD, which changes the flag at the beginning of atomic_enable and atomic_disable instead. > > Best regards, > Krzysztof
diff --git a/drivers/gpu/drm/exynos/exynos7_drm_decon.c b/drivers/gpu/drm/exynos/exynos7_drm_decon.c index e994779694f0..2c4ee87ae6ec 100644 --- a/drivers/gpu/drm/exynos/exynos7_drm_decon.c +++ b/drivers/gpu/drm/exynos/exynos7_drm_decon.c @@ -152,7 +152,7 @@ static void decon_commit(struct exynos_drm_crtc *crtc) struct drm_display_mode *mode = &crtc->base.state->adjusted_mode; u32 val, clkdiv; - if (ctx->suspended) + if (!ctx->suspended) return; /* nothing to do if we haven't set the mode yet */
decon_commit() gets called during atomic_enable. At this stage, DECON is suspended, and thus the function refuses to run. Fix the suspended condition checking in decon_commit(). Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org> --- drivers/gpu/drm/exynos/exynos7_drm_decon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)