[PATCH v6 2/6] drm/msm/dpu: adjust data width for widen bus case

From: Jun Nie
Date: Thu May 30 2024 - 01:57:27 EST


data is valid for only half the active window if widebus
is enabled

Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> # on SM8650-QRD
Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> # on SM8650-HDK
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
index 225c1c7768ff..f97221423249 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
@@ -168,6 +168,15 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *intf,

data_width = p->width;

+ /*
+ * If widebus is enabled, data is valid for only half the active window
+ * since the data rate is doubled in this mode. But for the compression
+ * mode in DP case, the p->width is already adjusted in
+ * drm_mode_to_intf_timing_params()
+ */
+ if (p->wide_bus_en && !dp_intf)
+ data_width = p->width >> 1;
+
hsync_data_start_x = hsync_start_x;
hsync_data_end_x = hsync_start_x + data_width - 1;


--
2.34.1