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[v2] drm: xlnx: zynqmp_dpsub: Enable plane in atomic update

Message ID 20240523-dp-layer-enable-v2-1-d799020098fc@amd.com (mailing list archive)
State New
Headers show
Series [v2] drm: xlnx: zynqmp_dpsub: Enable plane in atomic update | expand

Commit Message

Anatoliy Klymenko May 23, 2024, 11:49 p.m. UTC 
Unconditionally enable the DPSUB layer in the corresponding atomic plane
update callback. Setting the new display mode may require disabling and
re-enabling the CRTC. This effectively resets DPSUB to the default state
with all layers disabled. The original implementation of the plane atomic
update enables the corresponding DPSUB layer only if the framebuffer
format has changed. This would leave the layer disabled after switching to
a different display mode with the same framebuffer format.

Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
---
Changes in v2:
- Added comment around DPSUB layer enablement explaining why it should be
  done unconditionally.
- Link to v1: https://lore.kernel.org/r/20240520-dp-layer-enable-v1-1-c9b481209115@amd.com
---
 drivers/gpu/drm/xlnx/zynqmp_kms.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)


---
base-commit: 673087d8b023faf34b84e8faf63bbeea3da87bab
change-id: 20240520-dp-layer-enable-7b561af29ca8

Best regards,
diff mbox series

Patch

diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c b/drivers/gpu/drm/xlnx/zynqmp_kms.c
index 43bf416b33d5..0b57ab5451a9 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_kms.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c
@@ -120,9 +120,13 @@  static void zynqmp_dpsub_plane_atomic_update(struct drm_plane *plane,
 		zynqmp_disp_blend_set_global_alpha(dpsub->disp, true,
 						   plane->state->alpha >> 8);
 
-	/* Enable or re-enable the plane if the format has changed. */
-	if (format_changed)
-		zynqmp_disp_layer_enable(layer);
+	/*
+	 * Unconditionally enable the layer, as it may have been disabled
+	 * previously either explicitly to reconfigure layer format, or
+	 * implicitly after DPSUB reset during display mode change. DRM
+	 * framework calls this callback for enabled planes only.
+	 */
+	zynqmp_disp_layer_enable(layer);
 }
 
 static const struct drm_plane_helper_funcs zynqmp_dpsub_plane_helper_funcs = {