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 <marex@xxxxxxx> Cc: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> Cc: Robert Foss <robert.foss@xxxxxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx --- NOTE: See the following: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/942005/sn65dsi83-dsi83-lvds-bridge---sporadic-behavior---no-video https://community.nxp.com/t5/i-MX-Processors/i-MX8M-MIPI-DSI-Interface-LVDS-Bridge-Initialization/td-p/1156533 --- 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 a32f70bc68ea4..4ea71d7f0bfbc 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c @@ -520,6 +520,11 @@ 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, -- 2.33.0
