[PATCH 0/6] drm/msm/dpu: Fixes for virtual planes and 1.x features

[PATCH 0/6] drm/msm/dpu: Fixes for virtual planes and 1.x features

[Vladimir Lypak]

This patch series fix some issues found during testing on MDSS v1.16.

Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
---
Vladimir Lypak (6):
      drm/msm/dpu: Fix allocation of RGB SSPPs without scaling
      drm/msm/dpu: Propagate error from dpu_assign_plane_resources
      drm/msm/dpu: Disable scaling for unsupported scaler types
      drm/msm/dpu: Fix pixel extension sub-sampling
      drm/msm/dpu: Require linear modifier for writeback framebuffers
      drm/msm/dpu: Disable broken YUV on QSEED2 hardware

 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c |  4 ++--
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c      | 14 ++++++++------
 drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c         |  2 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c  |  3 +++
 4 files changed, 14 insertions(+), 9 deletions(-)
---
base-commit: 6f3b6e91f7201e248d83232538db14d30100e9c7
change-id: 20251016-b4-dpu-fixes-c847c48e0e5d

Best regards,
-- 
Vladimir Lypak <vladimir.lypak@gmail.com>

[PATCH 1/6] drm/msm/dpu: Fix allocation of RGB SSPPs without scaling

[Vladimir Lypak]

Due to condition in dpu_rm_reserve_sspp, RGB SSPPs are only tried when
scaling is requested, which prevents those SSPPs from being reserved if
we don't need scaling at all. Instead we should check if YUV support is
requested, since scaling on RGB SSPPs is optional and is not implemented
in driver yet.

Fixes: 774bcfb73176 ("drm/msm/dpu: add support for virtual planes")
Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
index 2c77c74fac0fda649da8ce19b7b3c6cb32b9535c..d9c3b0a1d0914a47f86ac9a854fbcede021e73cb 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
@@ -842,7 +842,7 @@ struct dpu_hw_sspp *dpu_rm_reserve_sspp(struct dpu_rm *rm,
 
 	if (!reqs->scale && !reqs->yuv)
 		hw_sspp = dpu_rm_try_sspp(rm, global_state, crtc, reqs, SSPP_TYPE_DMA);
-	if (!hw_sspp && reqs->scale)
+	if (!hw_sspp && !reqs->yuv)
 		hw_sspp = dpu_rm_try_sspp(rm, global_state, crtc, reqs, SSPP_TYPE_RGB);
 	if (!hw_sspp)
 		hw_sspp = dpu_rm_try_sspp(rm, global_state, crtc, reqs, SSPP_TYPE_VIG);

-- 
2.51.0

Re: [PATCH 1/6] drm/msm/dpu: Fix allocation of RGB SSPPs without scaling

[Dmitry Baryshkov]

On Fri, Oct 17, 2025 at 07:58:35PM +0000, Vladimir Lypak wrote:
> Due to condition in dpu_rm_reserve_sspp, RGB SSPPs are only tried when
> scaling is requested, which prevents those SSPPs from being reserved if
> we don't need scaling at all. Instead we should check if YUV support is
> requested, since scaling on RGB SSPPs is optional and is not implemented
> in driver yet.
> 
> Fixes: 774bcfb73176 ("drm/msm/dpu: add support for virtual planes")
> Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

[PATCH 2/6] drm/msm/dpu: Propagate error from dpu_assign_plane_resources

[Vladimir Lypak]

The dpu_plane_virtual_assign_resources function might fail if there is
no suitable SSPP(s) for the plane. This leaves sspp field in plane
state uninitialized and later leads to NULL dereference during commit:

Call trace:
 _dpu_crtc_blend_setup+0x194/0x620 [msm] (P)
 dpu_crtc_atomic_begin+0xe4/0x240 [msm]
 drm_atomic_helper_commit_planes+0x88/0x358
 msm_atomic_commit_tail+0x1b4/0x8b8 [msm]
 commit_tail+0xa8/0x1b0
 drm_atomic_helper_commit+0x180/0x1a0
 drm_atomic_commit+0x94/0xe0
 drm_mode_atomic_ioctl+0xa88/0xd60
 drm_ioctl_kernel+0xc4/0x138
 drm_ioctl+0x364/0x4f0
 __arm64_sys_ioctl+0xac/0x108
 invoke_syscall.constprop.0+0x48/0x100
 el0_svc_common.constprop.0+0x40/0xe8
 do_el0_svc+0x24/0x38
 el0_svc+0x30/0xe0
 el0t_64_sync_handler+0xa0/0xe8
 el0t_64_sync+0x198/0x1a0

Fixes: 3ed12a3664b3 ("drm/msm/dpu: allow sharing SSPP between planes")
Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index f54cf0faa1c7c8c00eb68b8b45ca2fc776f7f62f..d198a65a2c5fef5fbdebc9c383a4b08bc71b8bf3 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -1278,7 +1278,7 @@ int dpu_assign_plane_resources(struct dpu_global_state *global_state,
 							     state, plane_state,
 							     prev_adjacent_plane_state);
 		if (ret)
-			break;
+			return ret;
 
 		prev_adjacent_plane_state = plane_state;
 	}

-- 
2.51.0

Re: [PATCH 2/6] drm/msm/dpu: Propagate error from dpu_assign_plane_resources

[Dmitry Baryshkov]

On Fri, Oct 17, 2025 at 07:58:36PM +0000, Vladimir Lypak wrote:
> The dpu_plane_virtual_assign_resources function might fail if there is
> no suitable SSPP(s) for the plane. This leaves sspp field in plane
> state uninitialized and later leads to NULL dereference during commit:
> 
> Call trace:
>  _dpu_crtc_blend_setup+0x194/0x620 [msm] (P)
>  dpu_crtc_atomic_begin+0xe4/0x240 [msm]
>  drm_atomic_helper_commit_planes+0x88/0x358
>  msm_atomic_commit_tail+0x1b4/0x8b8 [msm]
>  commit_tail+0xa8/0x1b0
>  drm_atomic_helper_commit+0x180/0x1a0
>  drm_atomic_commit+0x94/0xe0
>  drm_mode_atomic_ioctl+0xa88/0xd60
>  drm_ioctl_kernel+0xc4/0x138
>  drm_ioctl+0x364/0x4f0
>  __arm64_sys_ioctl+0xac/0x108
>  invoke_syscall.constprop.0+0x48/0x100
>  el0_svc_common.constprop.0+0x40/0xe8
>  do_el0_svc+0x24/0x38
>  el0_svc+0x30/0xe0
>  el0t_64_sync_handler+0xa0/0xe8
>  el0t_64_sync+0x198/0x1a0
> 
> Fixes: 3ed12a3664b3 ("drm/msm/dpu: allow sharing SSPP between planes")
> Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

[PATCH 3/6] drm/msm/dpu: Disable scaling for unsupported scaler types

[Vladimir Lypak]

Scaling is not implemented for some type of scalers (QSEED2 and RGB) but
it was unintentionally re-enabled with change below. The remaining
condition in dpu_plane_atomic_check_pipe is not enough because it only
checks for length of scaler block (which is present). This patch adds a
additional check for setup_scaler operation.

Fixes: 8f15005783b8 ("drm/msm/dpu: move scaling limitations out of the hw_catalog")
Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index d198a65a2c5fef5fbdebc9c383a4b08bc71b8bf3..6effe0fa4837284a1f038e4907c4c91d239aeb8b 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -740,7 +740,7 @@ static int dpu_plane_atomic_check_pipe(struct dpu_plane *pdpu,
 	 * We already have verified scaling against platform limitations.
 	 * Now check if the SSPP supports scaling at all.
 	 */
-	if (!sblk->scaler_blk.len &&
+	if (!(sblk->scaler_blk.len && pipe->sspp->ops.setup_scaler) &&
 	    ((drm_rect_width(&new_plane_state->src) >> 16 !=
 	      drm_rect_width(&new_plane_state->dst)) ||
 	     (drm_rect_height(&new_plane_state->src) >> 16 !=

-- 
2.51.0

Re: [PATCH 3/6] drm/msm/dpu: Disable scaling for unsupported scaler types

[Dmitry Baryshkov]

On Fri, Oct 17, 2025 at 07:58:37PM +0000, Vladimir Lypak wrote:
> Scaling is not implemented for some type of scalers (QSEED2 and RGB) but
> it was unintentionally re-enabled with change below. The remaining
> condition in dpu_plane_atomic_check_pipe is not enough because it only
> checks for length of scaler block (which is present). This patch adds a
> additional check for setup_scaler operation.

Nit: in future please refrain from using constructions like 'This patch
makes foo' (see Documentation/process/submitting-patches.rst).

For this patch:

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


> 
> Fixes: 8f15005783b8 ("drm/msm/dpu: move scaling limitations out of the hw_catalog")
> Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

-- 
With best wishes
Dmitry

[PATCH 4/6] drm/msm/dpu: Fix pixel extension sub-sampling

[Vladimir Lypak]

In _dpu_plane_setup_pixel_ext function instead of dividing just chroma
source resolution once (component 1 and 2), second component is divided
once more because src_w and src_h variable is reused between iterations.
Third component receives wrong source resolution too (from component 2).
To fix this introduce temporary variables for each iteration.

Fixes: dabfdd89eaa9 ("drm/msm/disp/dpu1: add inline rotation support for sc7280")
Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index 6effe0fa4837284a1f038e4907c4c91d239aeb8b..905524ceeb1f192c093f1be7f571b29eb4b53379 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -500,13 +500,15 @@ static void _dpu_plane_setup_pixel_ext(struct dpu_hw_scaler3_cfg *scale_cfg,
 	int i;
 
 	for (i = 0; i < DPU_MAX_PLANES; i++) {
+		uint32_t w = src_w, h = src_h;
+
 		if (i == DPU_SSPP_COMP_1_2 || i == DPU_SSPP_COMP_2) {
-			src_w /= chroma_subsmpl_h;
-			src_h /= chroma_subsmpl_v;
+			w /= chroma_subsmpl_h;
+			h /= chroma_subsmpl_v;
 		}
 
-		pixel_ext->num_ext_pxls_top[i] = src_h;
-		pixel_ext->num_ext_pxls_left[i] = src_w;
+		pixel_ext->num_ext_pxls_top[i] = h;
+		pixel_ext->num_ext_pxls_left[i] = w;
 	}
 }
 

-- 
2.51.0

Re: [PATCH 4/6] drm/msm/dpu: Fix pixel extension sub-sampling

[Dmitry Baryshkov]

On Fri, Oct 17, 2025 at 07:58:38PM +0000, Vladimir Lypak wrote:
> In _dpu_plane_setup_pixel_ext function instead of dividing just chroma
> source resolution once (component 1 and 2), second component is divided
> once more because src_w and src_h variable is reused between iterations.
> Third component receives wrong source resolution too (from component 2).
> To fix this introduce temporary variables for each iteration.
> 
> Fixes: dabfdd89eaa9 ("drm/msm/disp/dpu1: add inline rotation support for sc7280")
> Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

[PATCH 5/6] drm/msm/dpu: Require linear modifier for writeback framebuffers

[Vladimir Lypak]

UBWC-related register configuration for writeback is not implemented in
the driver yet but there aren't any checks for non-linear modifiers in
atomic_check. Thus when compressed framebuffer is attached to writeback
connector it will be filled with linear image data. This patch forbids
non-linear modifiers for writeback framebuffers until UBWC support for
writeback is properly implemented.

Fixes: 71174f362d67 ("drm/msm/dpu: move writeback's atomic_check to dpu_writeback.c")
Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
index cd73468e369a93c50303db2a7d4499bcb17be5d1..7545c0293efbd8f7eb34a4ac56f616b7cadae1c0 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
@@ -72,6 +72,9 @@ static int dpu_wb_conn_atomic_check(struct drm_connector *connector,
 		DPU_ERROR("invalid fb w=%d, maxlinewidth=%u\n",
 			  fb->width, dpu_wb_conn->maxlinewidth);
 		return -EINVAL;
+	} else if (fb->modifier != DRM_FORMAT_MOD_LINEAR) {
+		DPU_ERROR("unsupported fb modifier:%#llx\n", fb->modifier);
+		return -EINVAL;
 	}
 
 	return drm_atomic_helper_check_wb_connector_state(conn_state->connector, conn_state->state);

-- 
2.51.0

Re: [PATCH 5/6] drm/msm/dpu: Require linear modifier for writeback framebuffers

[Dmitry Baryshkov]

On Fri, Oct 17, 2025 at 07:58:39PM +0000, Vladimir Lypak wrote:
> UBWC-related register configuration for writeback is not implemented in
> the driver yet but there aren't any checks for non-linear modifiers in
> atomic_check. Thus when compressed framebuffer is attached to writeback
> connector it will be filled with linear image data. This patch forbids
> non-linear modifiers for writeback framebuffers until UBWC support for
> writeback is properly implemented.
> 
> Fixes: 71174f362d67 ("drm/msm/dpu: move writeback's atomic_check to dpu_writeback.c")
> Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 3 +++
>  1 file changed, 3 insertions(+)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

[PATCH 6/6] drm/msm/dpu: Disable broken YUV on QSEED2 hardware

[Vladimir Lypak]

YUV formats on this hardware needs scaling for chroma planes. However it
is not implemented for QSEED2 which breaks display pipeline if YUV format
is used (causing partial and corrupted output with PPDONE timeouts).
This patch temporarily disables YUV by switching affected sub-block to
RGB only format list.

Fixes: daf9a92daeb8 ("drm/msm/dpu: Add support for MSM8996")
Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
index 6641455c4ec6a2d082644f1488ea5f5605ccc208..9f8d1bba9139a7e09ee321cf1b6f30f96890918f 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
@@ -267,8 +267,8 @@ static const u32 wb2_formats_rgb_yuv[] = {
 		.base = 0x200, .len = 0xa0,}, \
 	.csc_blk = {.name = "csc", \
 		.base = 0x320, .len = 0x100,}, \
-	.format_list = plane_formats_yuv, \
-	.num_formats = ARRAY_SIZE(plane_formats_yuv), \
+	.format_list = plane_formats, \
+	.num_formats = ARRAY_SIZE(plane_formats), \
 	.rotation_cfg = NULL, \
 	}
 

-- 
2.51.0

Re: [PATCH 6/6] drm/msm/dpu: Disable broken YUV on QSEED2 hardware

[Dmitry Baryshkov]

On Sat, Oct 18, 2025 at 02:33:43PM +0000, Vladimir Lypak wrote:
> YUV formats on this hardware needs scaling for chroma planes. However it
> is not implemented for QSEED2 which breaks display pipeline if YUV format
> is used (causing partial and corrupted output with PPDONE timeouts).
> This patch temporarily disables YUV by switching affected sub-block to
> RGB only format list.
> 
> Fixes: daf9a92daeb8 ("drm/msm/dpu: Add support for MSM8996")
> Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Does it apply to all QSEED2 platforms or just some of them?

-- 
With best wishes
Dmitry

Re: [PATCH 6/6] drm/msm/dpu: Disable broken YUV on QSEED2 hardware

[Dmitry Baryshkov]

On Sat, Oct 18, 2025 at 02:33:43PM +0000, Vladimir Lypak wrote:
> YUV formats on this hardware needs scaling for chroma planes. However it
> is not implemented for QSEED2 which breaks display pipeline if YUV format
> is used (causing partial and corrupted output with PPDONE timeouts).
> This patch temporarily disables YUV by switching affected sub-block to
> RGB only format list.
> 
> Fixes: daf9a92daeb8 ("drm/msm/dpu: Add support for MSM8996")
> Signed-off-by: Vladimir Lypak <vladimir.lypak@gmail.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

Re: [PATCH 0/6] drm/msm/dpu: Fixes for virtual planes and 1.x features

[Dmitry Baryshkov]

On Fri, 17 Oct 2025 19:58:34 +0000, Vladimir Lypak wrote:
> This patch series fix some issues found during testing on MDSS v1.16.
> 
> 

Applied, thanks!

[1/6] drm/msm/dpu: Fix allocation of RGB SSPPs without scaling
      https://gitlab.freedesktop.org/lumag/msm/-/commit/2319551e97f0
[2/6] drm/msm/dpu: Propagate error from dpu_assign_plane_resources
      https://gitlab.freedesktop.org/lumag/msm/-/commit/23ab0d6228bf
[3/6] drm/msm/dpu: Disable scaling for unsupported scaler types
      https://gitlab.freedesktop.org/lumag/msm/-/commit/425da3305972
[4/6] drm/msm/dpu: Fix pixel extension sub-sampling
      https://gitlab.freedesktop.org/lumag/msm/-/commit/2f8bed917542
[5/6] drm/msm/dpu: Require linear modifier for writeback framebuffers
      https://gitlab.freedesktop.org/lumag/msm/-/commit/5e0656b12534
[6/6] drm/msm/dpu: Disable broken YUV on QSEED2 hardware
      https://gitlab.freedesktop.org/lumag/msm/-/commit/bbc65d1bde82

Best regards,
-- 
With best wishes
Dmitry