From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1F0CBC433F5 for ; Sun, 13 Feb 2022 02:27:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0D5EA10E1A6; Sun, 13 Feb 2022 02:27:06 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) by gabe.freedesktop.org (Postfix) with ESMTPS id 86C3810E1A6 for ; Sun, 13 Feb 2022 02:27:04 +0000 (UTC) Received: from tr.lan (ip-89-176-112-137.net.upcbroadband.cz [89.176.112.137]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 3A1A983095; Sun, 13 Feb 2022 03:27:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1644719222; bh=9zhagREQC9QDVIBVCcMDLxnDGxs/W1+y6okQrZrfq2Y=; h=From:To:Cc:Subject:Date:From; b=GY+9lQNW/FcAGNAkZMx7+jeQwK7Lh4Z/SBswUzs+yagK9DjzHog7F6/mqylvB9LhR J0sDsaCT4FPyQvI7xSCVOcXFzTc2mEuXczcnIAtMnMgFiuixCb9KKc/cfSVzCnClMy g3/aJUhZflxOttuR5Ivm909HtSdLkhpCyTV+9p24YD9bk4x5tPZ9NSV8xtPp40fqWi HjDdJakUyOXZHvZTIJ9dCOGRx+cuSAB4ST94Tx5obpFpwJPsuWqB9Cl1IHvFNeIGS9 8P7P5+zZHN7s5hGwAa1YM88ECbn5My7ysDDvtXPmhxmHzYq3HWZHRt0kUIcAibVzDw JXEfpKsoeCJCQ== From: Marek Vasut To: dri-devel@lists.freedesktop.org Subject: [PATCH][RESEND] drm/bridge: ti-sn65dsi83: Check link status register after enabling the bridge Date: Sun, 13 Feb 2022 03:26:48 +0100 Message-Id: <20220213022648.495895-1-marex@denx.de> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Virus-Scanned: clamav-milter 0.103.5 at phobos.denx.de X-Virus-Status: Clean X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marek Vasut , Robert Foss , Jagan Teki , Sam Ravnborg , Laurent Pinchart Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 --- 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 19daaddd29a41..1d7c154ea1d79 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, -- 2.34.1