[Freedreno] [PATCH] drm/msm/dsi: Enable BURST_MODE for command mode for DSI 6G v1.3+

Jessica Zhang quic_jesszhan at quicinc.com
Mon Jun 12 23:37:36 UTC 2023


During a frame transfer in command mode, there could be frequent
LP11 <-> HS transitions when multiple DCS commands are sent mid-frame or
if the DSI controller is running on slow clock and is throttled. To
minimize frame latency due to these transitions, it is recommended to
send the frame in a single burst.

This feature is supported for DSI 6G 1.3 and above, thus enable burst
mode if supported.

Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>
---
 drivers/gpu/drm/msm/dsi/dsi_host.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 744f2398a6d6..8254b06dca85 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -994,6 +994,11 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
 		dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM0_TOTAL,
 			DSI_CMD_MDP_STREAM0_TOTAL_H_TOTAL(hdisplay) |
 			DSI_CMD_MDP_STREAM0_TOTAL_V_TOTAL(mode->vdisplay));
+
+		if (msm_host->cfg_hnd->major == MSM_DSI_VER_MAJOR_6G &&
+				msm_host->cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V1_3)
+			dsi_write(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2,
+					DSI_CMD_MODE_MDP_CTRL2_BURST_MODE);
 	}
 }
 

---
base-commit: dd969f852ba4c66938c71889e826aa8e5300d2f2
change-id: 20230608-b4-add-burst-mode-a5bb144069fa

Best regards,
-- 
Jessica Zhang <quic_jesszhan at quicinc.com>



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