Re: [PATCH v7 0/3] Fix degradation problem of alpha blending series

["Jason-JH Lin (林睿祥)" <Jason-JH.Lin@mediatek.com>]

Hi Alper,

On Sat, 2024-09-28 at 16:02 +0300, Alper Nebi Yasak wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  Hi,
> 
> On 2024-09-26 13:22 +03:00, Jason-JH.Lin wrote:
> > Some SoCs not support pre-multiplied pixel formats and extending
> > configuration of OVL pre-multiplied color formats, such as MT8173.
> > 
> > Fix the SoC degradation problem by this sreies.
> > 
> > ---
> > 
> > Change in v7:
> > 1. Add the remove color format comment patch for OVL
> > 2. Fix warning: 'const' type qualifier on return type has no effect
> > 
> > [...]
> 
> I get warnings and "*ERROR* failed to create property: blend_mode" a
> few 
> times until mediatek-drm initializes. It happens on MT8173 and
> MT8183, but 
> not on MT8186. Colors are correct, though. (I'm tempted to add
> Tested-by.)
> 

MT8186 is using MT8192's compatible name, so its blend_modes suppots
pre-multiplied.

> ------8<------
> 
> From MT8173:
> 
> [  +0.017201] ------------[ cut here ]------------
> [  +0.009250] WARNING: CPU: 3 PID: 37 at
> drivers/gpu/drm/drm_blend.c:586
> drm_plane_create_blend_mode_property+0xf0/0x110 [drm]
> [  +0.022533] Modules linked in: [...]
> [  +0.158166] CPU: 3 UID: 0 PID: 37 Comm: kworker/u16:1 Tainted:
> G        W          6.11.0-next-20240927-deb-00006-ge514a0f89dd9 #
> [  +0.023542] Tainted: [W]=WARN
> [  +0.005936] Hardware name: Google Hana (DT)
> [  +0.008379] Workqueue: events_unbound deferred_probe_work_func
> [  +0.011694] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [  +0.013959] pc : drm_plane_create_blend_mode_property+0xf0/0x110
> [drm]
> [  +0.013111] lr : mtk_plane_init+0xf4/0x198 [mediatek_drm]
> [  +0.010829] sp : ffff800081d538c0
> [  +0.006634] x29: ffff800081d538c0 x28: ffff0000c431e080 x27:
> ffff0000c19787a8
> [  +0.014314] x26: 0000000000000548 x25: 0000000000000006 x24:
> ffff0000c431f000
> [  +0.014317] x23: 0000000000000035 x22: 0000000000000006 x21:
> ffff0000c0ca1058
> [  +0.014313] x20: 0000000000000006 x19: 0000000000000000 x18:
> ffffffffffffffff
> [  +0.014314] x17: 6f72702065746165 x16: 7263206f74206465 x15:
> ffff0000c414e626
> [  +0.014316] x14: 0000000000000000 x13: 0000000000000028 x12:
> 0101010101010101
> [  +0.014313] x11: 7f7f7f7f7f7f7f7f x10: fefefeff726e6f79 x9 :
> ffff800079e689dc
> [  +0.014316] x8 : ffff0000c5875554 x7 : 00000000eeeeeeee x6 :
> 00000000c0c0c0c0
> [  +0.014314] x5 : 0000000000000000 x4 : ffff0000c0ca1190 x3 :
> ffff0000c0ca1190
> [  +0.014313] x2 : 000000000000ffff x1 : 0000000000000006 x0 :
> ffff0000c0ca1058
> [  +0.014314] Call trace:
> [  +0.004891]  drm_plane_create_blend_mode_property+0xf0/0x110 [drm]
> [  +0.012415]  mtk_plane_init+0xf4/0x198 [mediatek_drm]
> [  +0.010132]  mtk_crtc_create+0x34c/0x858 [mediatek_drm]
> [  +0.010479]  mtk_drm_bind+0x4b4/0x600 [mediatek_drm]
> [  +0.009956]  try_to_bring_up_aggregate_device+0x21c/0x2e8
> [  +0.010825]  __component_add+0xc0/0x1c0
> [  +0.007685]  component_add+0x1c/0x38
> [  +0.007163]  mtk_disp_rdma_probe+0x148/0x230 [mediatek_drm]
> [  +0.011175]  platform_probe+0x70/0xe8
> [  +0.007338]  really_probe+0xc8/0x3a0
> [  +0.007161]  __driver_probe_device+0x84/0x160
> [  +0.008730]  driver_probe_device+0x44/0x130
> [  +0.008379]  __device_attach_driver+0xc4/0x170
> [  +0.008905]  bus_for_each_drv+0x90/0x100
> [  +0.007855]  __device_attach+0xa8/0x1c8
> [  +0.007685]  device_initial_probe+0x1c/0x30
> [  +0.008380]  bus_probe_device+0xb0/0xc0
> [  +0.007683]  deferred_probe_work_func+0xbc/0x120
> [  +0.009253]  process_one_work+0x178/0x3d0
> [  +0.008033]  worker_thread+0x200/0x3f0
> [  +0.007511]  kthread+0xe8/0xf8
> [  +0.006115]  ret_from_fork+0x10/0x20
> [  +0.007164] ---[ end trace 0000000000000000 ]---
> [  +0.009278] [drm:mtk_plane_init [mediatek_drm]] *ERROR* failed to
> create property: blend_mode
> 
> From MT8183:
> 
> [   13.936989] ------------[ cut here ]------------
> [   13.946224] WARNING: CPU: 5 PID: 60 at
> drivers/gpu/drm/drm_blend.c:586
> drm_plane_create_blend_mode_property+0xf0/0x110 [drm]
> [   13.968714] Modules linked in: [...]
> [   14.116814] CPU: 5 UID: 0 PID: 60 Comm: kworker/u34:2 Tainted:
> G        W          6.11.0-next-20240927-deb-00006-ge514a0f89dd9 #1
> [   14.140323] Tainted: [W]=WARN
> [   14.146248] Hardware name: Google cozmo board (DT)
> [   14.155830] Workqueue: events_unbound deferred_probe_work_func
> [   14.167505] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [   14.181440] pc : drm_plane_create_blend_mode_property+0xf0/0x110
> [drm]
> [   14.194529] lr : mtk_plane_init+0xf4/0x188 [mediatek_drm]
> [   14.205338] sp : ffff8000804a3860
> [   14.211960] x29: ffff8000804a3860 x28: ffff715445288080 x27:
> ffff7154417fa748
> [   14.226247] x26: 0000000000000548 x25: 0000000000000006 x24:
> ffff71544528a000
> [   14.240536] x23: 0000000000000035 x22: 0000000000000006 x21:
> ffff715445a49ae8
> [   14.254822] x20: 0000000000000006 x19: 0000000000000000 x18:
> ffffffffffffffff
> [   14.269110] x17: 6f72702065746165 x16: ffffd6facceae8c0 x15:
> ffff715470421d46
> [   14.283398] x14: 0000000000000000 x13: 0000000000000028 x12:
> 0101010101010101
> [   14.297686] x11: 7f7f7f7f7f7f7f7f x10: fefefeff726e6f79 x9 :
> ffffd6fa92d179dc
> [   14.311973] x8 : ffff715445156ad4 x7 : 00000000eeeeeeee x6 :
> 00000000c0c0c0c0
> [   14.326261] x5 : 0000000000000000 x4 : ffff715445a49c20 x3 :
> ffff715445a49c20
> [   14.340549] x2 : 000000000000ffff x1 : 0000000000000006 x0 :
> ffff715445a49ae8
> [   14.354837] Call trace:
> [   14.359718]  drm_plane_create_blend_mode_property+0xf0/0x110 [drm]
> [   14.372111]  mtk_plane_init+0xf4/0x188 [mediatek_drm]
> [   14.382224]  mtk_crtc_create+0x34c/0x858 [mediatek_drm]
> [   14.392685]  mtk_drm_bind+0x51c/0x600 [mediatek_drm]
> [   14.402622]  try_to_bring_up_aggregate_device+0x21c/0x2e8
> [   14.413425]  __component_add+0xc0/0x1c0
> [   14.421094]  component_add+0x1c/0x38
> [   14.428241]  mtk_dsi_host_attach+0x80/0xe0 [mediatek_drm]
> [   14.439049]  devm_mipi_dsi_attach+0x3c/0xa0
> [   14.447413]  anx7625_link_bridge+0xfc/0x1c8 [anx7625]
> [   14.457522]  dp_aux_ep_probe+0x54/0x110 [drm_dp_aux_bus]
> [   14.468150]  really_probe+0xc8/0x3a0
> [   14.475296]  __driver_probe_device+0x84/0x160
> [   14.484009]  driver_probe_device+0x44/0x130
> [   14.492374]  __device_attach_driver+0xc4/0x170
> [   14.501261]  bus_for_each_drv+0x90/0x100
> [   14.509103]  __device_attach+0xa8/0x1c8
> [   14.516772]  device_initial_probe+0x1c/0x30
> [   14.525137]  bus_probe_device+0xb0/0xc0
> [   14.532805]  deferred_probe_work_func+0xbc/0x120
> [   14.542040]  process_one_work+0x178/0x3d0
> [   14.550059]  worker_thread+0x200/0x3f0
> [   14.557553]  kthread+0xe8/0xf8
> [   14.563656]  ret_from_fork+0x10/0x20
> [   14.570803] ---[ end trace 0000000000000000 ]---
> [   14.580052] [drm:mtk_plane_init [mediatek_drm]] *ERROR* failed to
> create property: blend_mode

Take a glimpse of drm_plane_create_blend_mode_property(), it can simply
find the reason here:
/**
 * drm_plane_create_blend_mode_property - create a new blend mode
property
 * @plane: drm plane
 * @supported_modes: bitmask of supported modes, must include
 *           BIT(DRM_MODE_BLEND_PREMULTI). Current DRM assumption is
 *           that alpha is premultiplied, and old userspace can break
if
 *           the property defaults to anything else.
 ...
 * RETURNS:
 * Zero for success or -errno
 */

int drm_plane_create_blend_mode_property(struct drm_plane *plane,
                     unsigned int supported_modes)
{
    unsigned int valid_mode_mask = BIT(DRM_MODE_BLEND_PIXEL_NONE) |
                                   BIT(DRM_MODE_BLEND_PREMULTI)   |
                                   BIT(DRM_MODE_BLEND_COVERAGE);
...

    if (WARN_ON((supported_modes & ~valid_mode_mask) ||
        ((supported_modes & BIT(DRM_MODE_BLEND_PREMULTI)) == 0)))
        return -EINVAL;
...
}

So I think if the SoCs don't support pre-multiplied color formats, then
just not create the blend_mode property and use the coverage mode color
format as default settings for OVL.

I'll send v8 for this.

Thanks for the verification on MT8173, MT8183 and MT8186.

Regards,
Jason-JH.Lin