From 85854fa95972455fd8ff340d7810dde57fe36d44 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sun, 13 Feb 2022 03:26:48 +0100 Subject: [PATCH] drm/bridge: ti-sn65dsi83: Check link status register after enabling the bridge In rare cases, the bridge may not start up correctly, which usually leads to no display output. In case this happens, warn about it in the kernel log. Signed-off-by: Marek Vasut Cc: Jagan Teki Cc: Laurent Pinchart Cc: Linus Walleij Cc: Robert Foss Cc: Sam Ravnborg Cc: dri-devel@lists.freedesktop.org Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20220213022648.495895-1-marex@denx.de --- drivers/gpu/drm/bridge/ti-sn65dsi83.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c index c2afef9..2831f08 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c @@ -488,6 +488,11 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge, /* Clear all errors that got asserted during initialization. */ regmap_read(ctx->regmap, REG_IRQ_STAT, &pval); regmap_write(ctx->regmap, REG_IRQ_STAT, pval); + + usleep_range(10000, 12000); + regmap_read(ctx->regmap, REG_IRQ_STAT, &pval); + if (pval) + dev_err(ctx->dev, "Unexpected link status 0x%02x\n", pval); } static void sn65dsi83_atomic_disable(struct drm_bridge *bridge, -- 2.7.4