[PATCH v4 2/5] drm: adjust data width for widen bus case

From: Jun Nie
Date: Fri May 24 2024 - 09:21:31 EST


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

Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c | 8 ++++++++
1 file changed, 8 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 2cf1f8c116b5..3d1bc8fa4ca2 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
@@ -167,6 +167,14 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *intf,
intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN;

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;

/* TODO: handle DSC+DP case, we only handle DSC+DSI case so far */
if (p->compression_en && !dp_intf)

--
2.34.1