From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from www537.your-server.de (www537.your-server.de [188.40.3.216]) (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 6C572368294; Tue, 21 Jul 2026 13:38:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=188.40.3.216 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784641113; cv=none; b=Eb8Qk6cEenvwCXJ+7k/Jf5ClFFaMrj8frKvksxK/FGg4IMRZSyZKEeYxGS78/g987IJFc01pshLw+3txhvBr+C9nWH+DjG71lVH6iYmxb60Ab+Tv3+HPglJDmWlNJwfHjUIcXL3L4hFBwgPEHXyoxcnVw+EczF4HFDsp1FCJ/HE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784641113; c=relaxed/simple; bh=n2R6rRuhuN8yu2y8ICNLxTuG14z+ZR0AEe0cXZNbk98=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=e2lVt8p8OKnIyK/3o3EwtoyfWp6TOYue9SpuwEjKj/DbuQtoiZJGf/aW8sO0jOPxasBXpSuvtpCihWAyK73YdSLmfm23ZgS2hIfy42hErP08G8vhsmlooN176tiive9947fVWkndNtfBFf0Uyopd4DQeSHsPRsPZRPAPPc0704o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ew.tq-group.com; spf=pass smtp.mailfrom=ew.tq-group.com; dkim=pass (2048-bit key) header.d=ew.tq-group.com header.i=@ew.tq-group.com header.b=nTDgUYmp; arc=none smtp.client-ip=188.40.3.216 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ew.tq-group.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ew.tq-group.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ew.tq-group.com header.i=@ew.tq-group.com header.b="nTDgUYmp" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=ew.tq-group.com; s=default2602; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID; bh=5vO8DsrbEViiyGukn8P28nsjF0//iyht0d3oo+GCY6I=; b=nTDgUYmpS4pJwaXpRPeoPxDgUb YlIAnD19CNIH9UJFw8gfmjKiFKXNJ/AFgYpmkJTk8K61NFMPa64c23RVdRQEYlsVp3YCemZv6HAh8 Zra8rYG00QZjQQtB5P8LNdbxiJAjFPLak2sBDlbT3GP9kTAVlZbVqVQk4WHiF1V1u7Y8JVXQrqEmh iFL8HG5EMj8fm6LB9VxeDHB1O1zMwtZfFjkAjEvCxoCJewFaM2RaFi5i61LZFhcEObJNa3TqlheJZ t2ZGG+B3St2Dk4quYFe80WcdWDiLjMA6wpoWh39JNWVz5jhsDUJNGcvZWTYfbFdsAV6KUdRIHQwQe QK3/NYOQ==; Received: from sslproxy02.your-server.de ([78.47.166.47]) by www537.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.96.2) (envelope-from ) id 1wmAfz-00020E-23; Tue, 21 Jul 2026 15:38:27 +0200 Received: from localhost ([127.0.0.1]) by sslproxy02.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wmAfz-000NuD-0t; Tue, 21 Jul 2026 15:38:27 +0200 From: Alexander Stein To: Mauro Carvalho Chehab , Sakari Ailus , Dave Stevenson , Richard Leitner Cc: Laurent Pinchart , Hans de Goede , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Leitner Subject: Re: [PATCH 2/2] media: ov9282: enable single-read I2C transactions Date: Tue, 21 Jul 2026 15:38:26 +0200 Message-ID: <2422477.ElGaqSPkdT@steina-w> Organization: TQ-Systems GmbH In-Reply-To: <20260721-cci-single-v1-2-8485171e1393@linux.dev> References: <20260721-cci-single-v1-0-8485171e1393@linux.dev> <20260721-cci-single-v1-2-8485171e1393@linux.dev> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" X-Virus-Scanned: Clear (ClamAV 1.4.3/28067/Tue Jul 21 08:23:56 2026) Hi Richard, thanks for addressing this long-standing issue. Am Dienstag, 21. Juli 2026, 15:25:29 CEST schrieb Richard Leitner: > Some OV9282 camera modules, such as those from Vision Components, fail > multi-byte register reads with the default CCI I2C regmap access pattern > and only work when single-register read transactions are used. This > results in the driver being unable to probe due to a chip id mismatch. >=20 > As the driver has no reliable way to identify affected modules enable > use_single_read for OV9282 unconditionally when creating the CCI regmap. What about a property in the DT instead? In DT it should be clear if a Vision Components camera is used. Best regards, Alexander >=20 > Tested on an i.M8MP system with OV9282 modules from Vision Components. >=20 > Signed-off-by: Richard Leitner > --- > drivers/media/i2c/ov9282.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) >=20 > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c > index 5b6f897a74fcd..8267a0a9c6f2d 100644 > --- a/drivers/media/i2c/ov9282.c > +++ b/drivers/media/i2c/ov9282.c > @@ -1283,6 +1283,11 @@ static int ov9282_probe(struct i2c_client *client) > struct ov9282 *ov9282; > int ret; > =20 > + const struct cci_regmap_config config =3D { > + .reg_addr_bits =3D 16, > + .use_single_read =3D true, > + }; > + > ov9282 =3D devm_kzalloc(&client->dev, sizeof(*ov9282), GFP_KERNEL); > if (!ov9282) > return -ENOMEM; > @@ -1301,7 +1306,7 @@ static int ov9282_probe(struct i2c_client *client) > return ret; > } > =20 > - ov9282->regmap =3D devm_cci_regmap_init_i2c(client, 16); > + ov9282->regmap =3D devm_cci_regmap_init_i2c_cfg(client, &config); > if (IS_ERR(ov9282->regmap)) > return dev_err_probe(ov9282->dev, PTR_ERR(ov9282->regmap), > "Failed to init CCI\n"); >=20 >=20 =2D-=20 TQ-Systems GmbH | M=FChlstra=DFe 2, Gut Delling | 82229 Seefeld, Germany Amtsgericht M=FCnchen, HRB 105018 Gesch=E4ftsf=FChrer: Detlef Schneider, R=FCdiger Stahl, Stefan Schneider http://www.tq-group.com/