From: Marek Vasut <marex@denx.de>
To: dri-devel@lists.freedesktop.org
Cc: Marek Vasut <marex@denx.de>,
Jagan Teki <jagan@amarulasolutions.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Linus Walleij <linus.walleij@linaro.org>,
Robert Foss <robert.foss@linaro.org>,
Sam Ravnborg <sam@ravnborg.org>
Subject: [PATCH] drm/bridge: ti-sn65dsi83: Check link status register after enabling the bridge
Date: Tue, 7 Sep 2021 04:39:48 +0200 [thread overview]
Message-ID: <20210907023948.871281-1-marex@denx.de> (raw)
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@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: dri-devel@lists.freedesktop.org
---
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
next reply other threads:[~2021-09-07 2:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-07 2:39 Marek Vasut [this message]
[not found] ` <CGME20210907073151eucas1p196543fbd114f34f6de700013fd0e4168@eucas1p1.samsung.com>
2021-09-07 7:31 ` [PATCH] drm/bridge: ti-sn65dsi83: Check link status register after enabling the bridge Andrzej Hajda
2021-09-07 14:25 ` Marek Vasut
2021-09-07 17:29 ` Andrzej Hajda
2021-09-07 21:24 ` Marek Vasut
2021-09-08 11:11 ` Dave Stevenson
2021-09-08 15:26 ` Marek Vasut
2021-09-08 16:13 ` Dave Stevenson
2021-09-08 21:14 ` Andrzej Hajda
2021-10-05 10:25 ` Dave Stevenson
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