From 993a87917c2af59efb0ee1ce43c878ca8790ba1c Mon Sep 17 00:00:00 2001 From: Jiri Vanek Date: Thu, 16 Jun 2022 00:22:21 +0200 Subject: [PATCH] drm/bridge/tc358775: Fix DSI clock division for vsync delay calculation Use the same PCLK divide option (divide DSI clock to generate pixel clock) which is set to LVDS Configuration Register (LVCFG) also for a VSync delay calculation. Without this change an auxiliary variable could underflow during the calculation for some dual-link LVDS panels and then calculated VSync delay is wrong. This leads to a shifted picture on a panel. Tested-by: Jiri Vanek Signed-off-by: Jiri Vanek Reviewed-by: Vinay Simha BN Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20220615222221.1501-3-jirivanek1@gmail.com --- drivers/gpu/drm/bridge/tc358775.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/tc358775.c b/drivers/gpu/drm/bridge/tc358775.c index 8909b820db0d4..7423b1b9d9612 100644 --- a/drivers/gpu/drm/bridge/tc358775.c +++ b/drivers/gpu/drm/bridge/tc358775.c @@ -430,7 +430,7 @@ static void tc_bridge_enable(struct drm_bridge *bridge) val = TC358775_VPCTRL_MSF(1); dsiclk = mode->crtc_clock * 3 * tc->bpc / tc->num_dsi_lanes / 1000; - clkdiv = dsiclk / DIVIDE_BY_3 * tc->lvds_link; + clkdiv = dsiclk / (tc->lvds_link == DUAL_LINK ? DIVIDE_BY_6 : DIVIDE_BY_3); byteclk = dsiclk / 4; t1 = hactive * (tc->bpc * 3 / 8) / tc->num_dsi_lanes; t2 = ((100000 / clkdiv)) * (hactive + hback_porch + hsync_len + hfront_porch) / 1000; -- 2.30.2