On 20/04/2023 20:47, Jeykumar Sankaran wrote:
On 4/19/2023 3:23 PM, Dmitry Baryshkov wrote:
On 19/04/2023 17:41, Arnaud Vrac wrote:
This avoids using two LMs instead of one when the display width is lower
than the maximum supported value. For example on MSM8996/MSM8998, the
actual maxwidth is 2560, so we would use two LMs for 1280x720 or
1920x1080 resolutions, while one is enough.
Signed-off-by: Arnaud Vrac <avrac@xxxxxxxxxx>
While this looks correct (and following what we have in 4.4), later
vendor kernels specify the topology explicitly. Probably we should
check this with the hw guys, because it might be the following case:
even though a single LM can supply the mode, it will spend more power
compared to two LMs.
Yes. 2 LM split will allow the HW to run in lower mdp core clock. Can
you maintain the split_threshold in the hw catalog until per mode
topology is available?
I don't think it warrants the trouble, unless we have a real usecase
when the device is short of LMs.
Arnaud, I'll mark this patch as Rejected for now, unless it fixes an LM
shortage for your platform.
Jeykumar S
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 1dc5dbe585723..dd2914726c4f6 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -53,8 +53,6 @@
#define IDLE_SHORT_TIMEOUT 1
-#define MAX_HDISPLAY_SPLIT 1080
-
/* timeout in frames waiting for frame done */
#define DPU_ENCODER_FRAME_DONE_TIMEOUT_FRAMES 5
@@ -568,10 +566,12 @@ static struct msm_display_topology
dpu_encoder_get_topology(
*/
if (intf_count == 2)
topology.num_lm = 2;
- else if (!dpu_kms->catalog->caps->has_3d_merge)
- topology.num_lm = 1;
+ else if (dpu_kms->catalog->caps->has_3d_merge &&
+ dpu_kms->catalog->mixer_count > 0 &&
+ mode->hdisplay > dpu_kms->catalog->mixer[0].sblk->maxwidth)
+ topology.num_lm = 2;
else
- topology.num_lm = (mode->hdisplay > MAX_HDISPLAY_SPLIT) ? 2
: 1;
+ topology.num_lm = 1;
if (crtc_state->ctm)
topology.num_dspp = topology.num_lm;
--
With best wishes
Dmitry
