Komeda leaves encoder->possible_clones unset, so it stays at 0 for every
encoder. When userspace asks for writeback, the DRM atomic checks
reject the configuration because no encoder is marked as clone-compatible,
leading to errors such as:
crtc96 failed valid clone check for mask 0x5
Komeda does not impose per-encoder clone restrictions, so initialize
possible_clones for all registered encoders to the full encoder mask
after encoder creation. This fixes writeback validation.
Signed-off-by: Asad Malik <[email protected]>
Signed-off-by: Raveendra Talabattula <[email protected]>
---
.../gpu/drm/arm/display/komeda/komeda_kms.c | 20 +++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index 6ed504099188..0dcc8c05e86b 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -276,7 +276,10 @@ struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev
*mdev)
{
struct komeda_kms_dev *kms;
struct drm_device *drm;
+ struct drm_encoder *encoder;
int err;
+ /* Bitmap of all encoders, assigned to each encoder's possible_clones.
*/
+ u32 clone_mask = 0;
kms = devm_drm_dev_alloc(mdev->dev, &komeda_kms_driver,
struct komeda_kms_dev, base);
@@ -311,6 +314,23 @@ struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev
*mdev)
drm_mode_config_reset(drm);
+ /*
+ * Build the full possible_clones mask once. drm_encoder_index()
+ * returns the bit position assigned to each encoder and BIT() converts
+ * that index into the corresponding mask value.
+ *
+ * Komeda does not have per-encoder clone restrictions, so every encoder
+ * gets the same mask and is advertised as clone-compatible with all
+ * other registered encoders.
+ */
+ drm_for_each_encoder(encoder, drm) {
+ clone_mask |= BIT(drm_encoder_index(encoder));
+ }
+
+ drm_for_each_encoder(encoder, drm) {
+ encoder->possible_clones = clone_mask;
+ }
+
err = devm_request_irq(drm->dev, mdev->irq,
komeda_kms_irq_handler, IRQF_SHARED,
drm->driver->name, drm);
--
2.43.0
