On Monday, 8 December 2025 03:48:24 Central European Standard Time Chaoyi Chen wrote:

Hello Nicolas, Daniel,

On 12/7/2025 4:45 AM, Nicolas Frattaroli wrote:

quoted

From: Daniel Stone <redacted>

Planes can only source AFBC framebuffers at multiples of 4px wide on
RK3566/RK3568. Instead of clipping on all SoCs when the user asks for an
unaligned source rectangle, reject the configuration in the plane's
atomic check on RK3566/RK3568 only.

Signed-off-by: Daniel Stone <redacted>
[Make RK3566/RK3568 specific, reword message]
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
index bc1ed0ffede0..e23213337104 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c

@@ -1076,6 +1076,13 @@ static int vop2_plane_atomic_check(struct drm_plane *plane,
 		return -EINVAL;
 	}
 
+	if (vop2->version == VOP_VERSION_RK3568 && drm_is_afbc(fb->modifier) && src_w % 4) {
+		drm_dbg_kms(vop2->drm,
+			    "AFBC source rectangles must be 4-byte aligned; is %d\n",
+			    src_w);
+		return -EINVAL;
+	}
+
 	return 0;
 }
 

@@ -1237,11 +1244,8 @@ static void vop2_plane_atomic_update(struct drm_plane *plane,
 	WARN_ON(src_w < 4);
 	WARN_ON(src_h < 4);
 
-	if (afbc_en && src_w % 4) {
-		drm_dbg_kms(vop2->drm, "vp%d %s src_w[%d] not 4 pixel aligned\n",
-			    vp->id, win->data->name, src_w);
-		src_w = ALIGN_DOWN(src_w, 4);
-	}
+	if (vop2->version == VOP_VERSION_RK3568 && drm_is_afbc(fb->modifier))
+		WARN_ON(src_w % 4);
 
 	act_info = (src_h - 1) << 16 | ((src_w - 1) & 0xffff);
 	dsp_info = (dsp_h - 1) << 16 | ((dsp_w - 1) & 0xffff);

You haven't replied to Andy's comment yet [0].

[0] https://lore.kernel.org/dri-devel/7b4e26ec.75f3.19a77276b53.Coremail.andyshrk@163.com/ (local)

Hello,

I addressed the follow-ups where it was clarified that the 4 pixel
limitation was RK3566/RK3568-only. I'm not going to bring back the
post-atomic_check modification for a fast path, but I'm open to
suggestions on how to do this differently.

One solution might be to modify the state with the ALIGN_DOWN stuff
in atomic_check instead, where userspace is then aware of the change
being done to its requested parameters. I'll need to double-check
whether this is in line with atomic modesetting's design.

Kind regards,
Nicolas Frattaroli