drm/bridge: synopsys: dw-mipi-dsi: Fix hcomponent lbcc for burst mode

In order to support burst mode, vendor drivers set lane_mbps higher than
bandwidth through DPI interface.  So, calculate horizontal component lane
byte clock cycle(lbcc) based on lane_mbps instead of pixel clock rate for
burst mode.

Fixes: ac87d23694f4 ("drm/bridge: synopsys: dw-mipi-dsi: Use pixel clock rate to calculate lbcc")
Reported-by: Heiko Stübner <heiko@sntech.de>
Closes: https://lore.kernel.org/linux-arm-kernel/5979575.UjTJXf6HLC@diego/T/#u
Tested-by: Heiko Stübner <heiko@sntech.de> # px30 minievb with xinpeng xpp055c272
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231018035212.1778767-1-victor.liu@nxp.com

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 8789eca261886f7ba98e704b2ce343614ed43512..824fb3c65742ef0a1f4d69a2a3939325c56d7acb 100644 (file)
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -774,13 +774,19 @@ static u32 dw_mipi_dsi_get_hcomponent_lbcc(struct dw_mipi_dsi *dsi,
        u32 frac, lbcc, minimum_lbcc;
        int bpp;
 
-       bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
-       if (bpp < 0) {
-               dev_err(dsi->dev, "failed to get bpp\n");
-               return 0;
-       }
+       if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) {
+               /* lbcc based on lane_mbps */
+               lbcc = hcomponent * dsi->lane_mbps * MSEC_PER_SEC / 8;
+       } else {
+               /* lbcc based on pixel clock rate */
+               bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
+               if (bpp < 0) {
+                       dev_err(dsi->dev, "failed to get bpp\n");
+                       return 0;
+               }
 
-       lbcc = div_u64((u64)hcomponent * mode->clock * bpp, dsi->lanes * 8);
+               lbcc = div_u64((u64)hcomponent * mode->clock * bpp, dsi->lanes * 8);
+       }
 
        frac = lbcc % mode->clock;
        lbcc = lbcc / mode->clock;