[RFC PATCH 11/13] drm/msm/disp/dpu1: Add support for DSC in topology

Vinod Koul
2021-05-21T12:54:00Z

For DSC to work we typically need a 2,2,1 configuration. This should
suffice for resolutions upto 4k. For more resolutions like 8k this won't
work.

Furthermore, we can use 1 DSC encoder in lesser resulutions, but that is
not power efficient according to Abhinav, so it is recommended to always
use 2 encoders.

So for now we blindly create 2,2,1 topology when DSC is enabled

Co-developed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 18cb1274a8bb..bffb40085c67 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -609,8 +609,22 @@ static struct msm_display_topology dpu_encoder_get_topology(
topology.num_enc = 0;
topology.num_intf = intf_count;

+ drm_enc = &dpu_enc->base;
+ priv = drm_enc->dev->dev_private;
+ if (priv && priv->dsc) {
+ /* In case of Display Stream Compression DSC, we would use
+ * 2 encoders, 2 line mixers and 1 interface
+ * this is power optimal and can drive upto (including) 4k
+ * screens
+ */
+ topology.num_enc = 2;
+ topology.num_intf = 1;
+ topology.num_lm = 2;
+ }
+
return topology;
}
+
static int dpu_encoder_virt_atomic_check(
struct drm_encoder *drm_enc,
struct drm_crtc_state *crtc_state,
--
2.26.3