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 633B521147C for ; Tue, 18 Mar 2025 21:00:33 +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=1742331638; cv=none; b=VXlnrmiO1ExXy/UXhKS2nackdrGYWUu4VOxVXk5GrQSjfGwfsghDxKsQjcA4UNHlvZe63HzHmBLnCp2LFPKmCHl6jZWrb6Ji2GliFt85C+RxtVejHLlm7790tGVXhR95zzpqefV8zeRfRUigT8p78wj4SNUITg3TFrum3AvYVxw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742331638; c=relaxed/simple; bh=jDbSn82C38j7+Xj6sOj+ms4Jc0IxsltW3mEpGzG+Ats=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eFllMdfQX3DzejcV/hWY9grcIjvCL0zwZ92ySu6kxSOYeVqw15XgRRprP2TlXKjTNfFS6jBr4X7sXAmD2tZRufJ3m6OZX/QjE6GbzKqVz1eJV9+VLP0EvQBYdhf9flRxZ/fcVNP/Yrpka0WfGSXSe12poH6QX0U65UzzthGOeaY= 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=S0XxPKkh; 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="S0XxPKkh" 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=Alm3 x2zwURgvPY8POW7lo0RkXBypewzaF7jaX9WC4CM=; b=S0XxPKkhONCFqnZSTTaL X9zmPmBUQ//QQdqFKPQxtBjW/jkRQUUkjNHHB2W8CAVnnakMNZq9aoud7S8jVG6O 0GWrMIzQfUqmE9ptUl6YpkwMK4iOMA6ed5J+RSfWMB34pKoX8E0lKEskvG2Tt46E zMUZQR4O9heU9K5yftfcrvBbqfr5JSCOF1dM+CTDPi86U+AF+7xy+CEcFy81fZwk 6+4uqF1UFBeogKmAkqJgD5yduG2aeDr/Ih5CAXx5euIDKIxez6TBjg0bIvVBVIlI 9XF7PS5L/3i3EK+I1iqqCNPU0+8YTfwICcqMj9pyBfewu/qQxlXqYEhqu7NS7tYL JQ== Received: (qmail 3995406 invoked from network); 18 Mar 2025 22:00:31 +0100 Received: by mail.zeus03.de with UTF8SMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 18 Mar 2025 22:00:31 +0100 X-UD-Smtp-Session: l3s3148p1@t5D0MaQwsrgujnsn Date: Tue, 18 Mar 2025 22:00:31 +0100 From: Wolfram Sang To: Laurent Pinchart Cc: linux-renesas-soc@vger.kernel.org, Douglas Anderson , Andrzej Hajda , Neil Armstrong , Robert Foss , 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 , Laurent Pinchart , linux-renesas-soc@vger.kernel.org, Douglas Anderson , Andrzej Hajda , Neil Armstrong , Robert Foss , 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> <20250318204133.GC22890@pendragon.ideasonboard.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="V93gJJxLrjmSUwfG" Content-Disposition: inline In-Reply-To: <20250318204133.GC22890@pendragon.ideasonboard.com> --V93gJJxLrjmSUwfG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Laurent, > > Read out and check the ID registers, so we can bail out if I2C > > communication does not work or if the device is unknown. >=20 > What's the advantage of that, what are you trying to guard against ? That a random chip at address 0x2c will be used. > > Tested on a > > Renesas GrayHawk board (R-Car V4M) by using a wrong I2C address and by > > not enabling RuntimePM for the device. >=20 > What do you mean by not enabling runtime PM for the device ? I left out pm_runtime_get() before regmap_read_bulk(). Happy hacking, Wolfram --V93gJJxLrjmSUwfG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmfZ3usACgkQFA3kzBSg KbY+DQ/8Dn0anJh88GbCa2wy1JyR1GyUnytfETCtm9KO3YrpEWmLUwnHANZz/rVP HRz8Gf6QY80ebWW7ZaclpPwet21iVYc+Vi4vJCOx0pNS5HTOKs1z8pSL+B8dof7w 5tH01QCTPNV4s88+0w3fH4rUaxzvmQKS6Uo+u9E8C+XTlofPORxl18ydImOkQ+cz 0x+g344T54BmbRt6tcFfEniueHGeBb6BOMa949eTXYwMx9sleqmVrljuiP+VJO5x Y2t3aKFZjlaFlnE2eNmRyLk+Uct11/dx5Ezdh5FpuobP9CfrXLvAHJQKPAMzAmNw v726M3M+ket5xFc14rGk7FRUIgRdKhs2PaZlIJxuNwiYqDrBZs9cVcpoXYd8FPih GCA6rdJlR+b3Sm9vEB6J8eV+ON40tP8GTSPkKdjgwDX/vSargDC5yPFLkwN2Xgd0 jzOi8M6eMow3tcyqWkedGwRvYTK9k+VA/ow0RVPWKpM2jzGk9xEjHyrrk+U1TE7T X2bcMZO0Z7X/Y4iIujFgSXlfjUZ/4A4v3myhjwqn3kQs5CqRlQbRDfxydfR0b3mS atN4MCGtIqQzwrq/9a2O2UunsI64bk59GQF5sYDMcQKYiyV3RYHfpjapg/X1a3vS IHF41DiZ2pS7BDcms/SsRVkrkQKQSZITsA09n0ltvbzUYHJQFXg= =kgfC -----END PGP SIGNATURE----- --V93gJJxLrjmSUwfG--