Hi, Justin:
AFBC just improve DRAM bandwidth performance, so I decide to backport this disable patch. Once fixup patch exist, then backport fixup patch.
Regards, CK
On Tue, 2025-10-28 at 10:48 +0000, Macpaul Lin (林智斌) wrote:
On Fri, 2025-10-24 at 17:27 -0300, Ariel D'Alessandro wrote:
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Commit c410fa9b07c32 ("drm/mediatek: Add AFBC support to Mediatek DRM driver") added AFBC support to Mediatek DRM and enabled the 32x8/split/sparse modifier.
However, this is currently broken on Mediatek MT8188 (Genio 700 EVK platform); tested using upstream Kernel and Mesa (v25.2.1), AFBC is used by default since Mesa v25.0.
Kernel trace reports vblank timeouts constantly, and the render is garbled:
[CRTC:62:crtc-0] vblank wait timed out WARNING: CPU: 7 PID: 70 at drivers/gpu/drm/drm_atomic_helper.c:1835 drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c [...] Hardware name: MediaTek Genio-700 EVK (DT) Workqueue: events_unbound commit_work pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c lr : drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c sp : ffff80008337bca0 x29: ffff80008337bcd0 x28: 0000000000000061 x27: 0000000000000000 x26: 0000000000000001 x25: 0000000000000000 x24: ffff0000c9dcc000 x23: 0000000000000001 x22: 0000000000000000 x21: ffff0000c66f2f80 x20: ffff0000c0d7d880 x19: 0000000000000000 x18: 000000000000000a x17: 000000040044ffff x16: 005000f2b5503510 x15: 0000000000000000 x14: 0000000000000000 x13: 74756f2064656d69 x12: 742074696177206b x11: 0000000000000058 x10: 0000000000000018 x9 : ffff800082396a70 x8 : 0000000000057fa8 x7 : 0000000000000cce x6 : ffff8000823eea70 x5 : ffff0001fef5f408 x4 : ffff80017ccee000 x3 : ffff0000c12cb480 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000c12cb480 Call trace: drm_atomic_helper_wait_for_vblanks.part.0+0x24c/0x27c (P) drm_atomic_helper_commit_tail_rpm+0x64/0x80 commit_tail+0xa4/0x1a4 commit_work+0x14/0x20 process_one_work+0x150/0x290 worker_thread+0x2d0/0x3ec kthread+0x12c/0x210 ret_from_fork+0x10/0x20 ---[ end trace 0000000000000000 ]---Until this gets fixed upstream, disable AFBC support on this platform, as it's currently broken with upstream Mesa.
Signed-off-by: Ariel D'Alessandro ariel.dalessandro@collabora.com
drivers/gpu/drm/mediatek/mtk_plane.c | 24 +----------------------- 1 file changed, 1 insertion(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_plane.c b/drivers/gpu/drm/mediatek/mtk_plane.c index 02349bd440017..788b52c1d10c5 100644 --- a/drivers/gpu/drm/mediatek/mtk_plane.c +++ b/drivers/gpu/drm/mediatek/mtk_plane.c @@ -21,9 +21,6 @@
static const u64 modifiers[] = { DRM_FORMAT_MOD_LINEAR, - DRM_FORMAT_MOD_ARM_AFBC(AFBC_FORMAT_MOD_BLOCK_SIZE_32x8 | - AFBC_FORMAT_MOD_SPLIT | - AFBC_FORMAT_MOD_SPARSE), DRM_FORMAT_MOD_INVALID, };
@@ -71,26 +68,7 @@ static bool mtk_plane_format_mod_supported(struct drm_plane *plane, uint32_t format, uint64_t modifier) { - if (modifier == DRM_FORMAT_MOD_LINEAR) - return true;
- if (modifier != DRM_FORMAT_MOD_ARM_AFBC( - AFBC_FORMAT_MOD_BLOCK_SIZE_32x8 | - AFBC_FORMAT_MOD_SPLIT | - AFBC_FORMAT_MOD_SPARSE)) - return false;
- if (format != DRM_FORMAT_XRGB8888 && - format != DRM_FORMAT_ARGB8888 && - format != DRM_FORMAT_BGRX8888 && - format != DRM_FORMAT_BGRA8888 && - format != DRM_FORMAT_ABGR8888 && - format != DRM_FORMAT_XBGR8888 && - format != DRM_FORMAT_RGB888 && - format != DRM_FORMAT_BGR888) - return false;
- return true; + return modifier == DRM_FORMAT_MOD_LINEAR; }
static void mtk_plane_destroy_state(struct drm_plane *plane,
Great! Thanks for this patch. I've tested this patch against k6.17.5 on mt8395-genio-1200-evk board, and it is working. I've also tested this patch with 'modetest -M mediatek -s 34@59:1200x1290' is working as well.
I'm not sure if it is possible to add a "Fixes:" tag to this patch? Maybe add this patch with 'Cc: stable@vger.kernel.org #6.17' at least? Some Linux distros are currently using 6.17 for testing.
Reviewed-by: Macpaul Lin macpaul.lin@mediatek.com
Regards, Macpaul Lin
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