drm/msm/dsi: Reuse earlier computed dsc->slice_chunk_size

dsi_populate_dsc_params() is called prior to dsi_update_dsc_timing() and
already computes a value for slice_chunk_size, whose value doesn't need
to be recomputed and re-set here.

Fixes: 08802f51 ("drm/msm/dsi: Add support for DSC configuration")
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Patchwork: https://patchwork.freedesktop.org/patch/508934/
Link: https://lore.kernel.org/r/20221026182824.876933-5-marijn.suijten@somainline.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/dsi/dsi_host.c

@@ -845,7 +845,6 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
 	u32 reg, reg_ctrl, reg_ctrl2;
 	u32 slice_per_intf, total_bytes_per_intf;
 	u32 pkt_per_line;
-	u32 bytes_in_slice;
 	u32 eol_byte_num;
 
 	/* first calculate dsc parameters and then program
@@ -860,11 +859,7 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
 	if (slice_per_intf > dsc->slice_count)
 		dsc->slice_count = 1;
 
-	bytes_in_slice = DIV_ROUND_UP(dsc->slice_width * dsc->bits_per_pixel, 8);
-
-	dsc->slice_chunk_size = bytes_in_slice;
-
-	total_bytes_per_intf = bytes_in_slice * slice_per_intf;
+	total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
 
 	eol_byte_num = total_bytes_per_intf % 3;
 	pkt_per_line = slice_per_intf / dsc->slice_count;
@@ -890,7 +885,7 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
 		reg_ctrl |= reg;
 
 		reg_ctrl2 &= ~DSI_COMMAND_COMPRESSION_MODE_CTRL2_STREAM0_SLICE_WIDTH__MASK;
-		reg_ctrl2 |= DSI_COMMAND_COMPRESSION_MODE_CTRL2_STREAM0_SLICE_WIDTH(bytes_in_slice);
+		reg_ctrl2 |= DSI_COMMAND_COMPRESSION_MODE_CTRL2_STREAM0_SLICE_WIDTH(dsc->slice_chunk_size);
 
 		dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL, reg_ctrl);
 		dsi_write(msm_host, REG_DSI_COMMAND_COMPRESSION_MODE_CTRL2, reg_ctrl2);