From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zeus03.de (zeus03.de [194.117.254.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6ED5206F23 for ; Tue, 18 Mar 2025 15:59:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.117.254.33 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742313556; cv=none; b=i2raFvD0YSbdupZlzouNXC/GPKJ4suPVWw3Q6MsN7KwrvtFdRaiGiLuJyFLMM9o8T8zao2Rfb2v//qdpg50LDYYRhdrvn9C1n3i1HnD6o9C2Ed/kFIKOCO+NHdVmHMluSG7W0eLDbRaKEkC1hbce2biVhyqpOILHGZ/rVOhQj9w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742313556; c=relaxed/simple; bh=l2xuRn7OiiPz3vpdQRM7Tp+8X45sv3JO2JtVTbGKDHk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jnMGhzvSGahdu6WXXsFlNwNuVEE2GyvkhegQ4d7Co3EKAMbh5d3AncKd+PexMUvevmNR3Pbno/0gjiBsCFPr1e2uMNW3wWEjXriu0ePHn257HYrSksNYm325ohJALuQ1cX+S8D0ixtu0dkDEIx+9Iiw/6rIYXrbUuCwR2Ix5cGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b=OAJPjh+B; arc=none smtp.client-ip=194.117.254.33 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b="OAJPjh+B" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=k1; bh=EI8C AoWPtyTWq68d7WhbQtJER/tz43L9sj9Vhci1h4g=; b=OAJPjh+BMDX4oJNdPKUC g1/ux/xj10WBwMEQ1iNo1oKHWFwSj7Hx99CvosqSeE3GZo7MqBAfdQFLWKE6DRY4 dFmCPPvdDhlGp7lI1R3R5/ojhnUnbOfPsxX9nYO9Je5jINkTnsEBFWoHVflFO7Sj tdtUyt4b/KK9ez9rShQ8N07yxbdlPmq5C8nUtRAw6XXgIbNN02tIqPNoFmn8g8eA sEcilnTiIu2cdXb/zmUyAQYiX/KuNKGhQwCu3BIHXhW92Dy6wQiSqhzsDyrLZJ4/ 3Gtel8ul6sfdy3WEhqJ1Oxs56FgkHhgbX+J2LtUWTMksKZjKwgxJOLVrz+SF4AWy jA== Received: (qmail 3861648 invoked from network); 18 Mar 2025 16:59:11 +0100 Received: by mail.zeus03.de with UTF8SMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 18 Mar 2025 16:59:11 +0100 X-UD-Smtp-Session: l3s3148p1@kb1S/J8wCqcgAwDPXyTHAJp038nK7dx+ Date: Tue, 18 Mar 2025 16:59:04 +0100 From: Wolfram Sang To: linux-renesas-soc@vger.kernel.org Cc: Douglas Anderson , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , dri-devel@lists.freedesktop.org Subject: Re: [PATCH v3] drm/bridge: ti-sn65dsi86: Check bridge connection failure Message-ID: Mail-Followup-To: Wolfram Sang , linux-renesas-soc@vger.kernel.org, Douglas Anderson , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , dri-devel@lists.freedesktop.org References: <20250318155549.19625-2-wsa+renesas@sang-engineering.com> Precedence: bulk X-Mailing-List: linux-renesas-soc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="QzI0E3h2wX4y6YOt" Content-Disposition: inline In-Reply-To: <20250318155549.19625-2-wsa+renesas@sang-engineering.com> --QzI0E3h2wX4y6YOt Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Mar 18, 2025 at 04:52:56PM +0100, Wolfram Sang wrote: > Read out and check the ID registers, so we can bail out if I2C > communication does not work or if the device is unknown. Tested on a > Renesas GrayHawk board (R-Car V4M) by using a wrong I2C address and by > not enabling RuntimePM for the device. >=20 > Signed-off-by: Wolfram Sang > --- >=20 > Changes since v2: > * switched to a new approach suggested by Doug (Thanks!). We add a > dedicated read instead of using the first read. This prevents creating > the aux devices. As a side-gain, we check now if the chip at the address > is really the one we want to support. Forgot to mention that it depends on my previous patch "[PATCH v2] drm/bridge: ti-sn65dsi86: make use of debugfs_init callback" --QzI0E3h2wX4y6YOt Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmfZmEMACgkQFA3kzBSg KbZMjRAAhiAgDtqYF+9mFQI48CwjmLxNofeRHvo5qQRsxJa3moZU8msl1qpCN4us OujgsaAIgjNXWUEvw1s9Ov+jI8XOsuylVeCx8+i7e2FMFt65XcIeMhta7APjKE31 L7DCFYw24SWjs3MDh9e7wKtS8tsSY2THATtwBaK4DdyHzzN29fdQI/XzLErB5Jwe Y/YgKSYtuvj34uHBjJQGZKP8fitbBceu8qkXiO/G/pidR1wJJwQ88zGgAVw1+TZb 0HYZLunzsDY1+8MHbwHe1SKfP9vSJm/V2/4nOK+fEG6DdEhrL6GrT+nO1elMXc67 WeyBLDbmoEvtYf+FzQsGhu8k66hzh4BxGcasE8g9c+RMXUfFcrgdqihsmH1MIR65 ctRtGA8Z6ddT+oDoy2yJgQd/22HqI2EOc5k0+E1lPM9iMVG4ZhgeCWJJOcqfk0o+ 8V6AtEm70xzQuocumnS/0c4F/jCKREQbOsxyHTMH10M+dCSiQJ49ZWU39axgUKiU /bW2tf+QcRHT44iKb3jewr/g3rpMnUKwT6hB59kjXv+3PsKxHj0W3EwopOiG7+gk Cqq9waNjlCf2iJoilYyFej9hOfaqvx6HiyiYMsWl+2IQCst7phelrNuejfR29mxM lrd5sKyOfpWfmHanyYu/jxwAJwl0a9tYoO/G8mPkx/Kk+D0Lp74= =PgR3 -----END PGP SIGNATURE----- --QzI0E3h2wX4y6YOt--