From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (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 53283325715; Fri, 23 Jan 2026 14:25:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769178340; cv=none; b=JJpdssE/Ak3jZB3h1QsqvPwvcm3MED5MKbKnLQcOxuR2cyn5F2I16/vAK4VEeALSjGdwdJVvQvQXM1TAuLvyZFBVq7WVnf42tQ5O8uZ5xLy5qjumTBEojdgoqisio8jShDstV/ctdbLnUZ9CM6BiwfNN2YY1VhA39MkF6lJDlJs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769178340; c=relaxed/simple; bh=Irvjef9/AWYaUeiQB1Npfq9HleYHezZV4pOTWj9W1HQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SY6IXjNl/LJZJgbKgK2TRfUR8Js9F8Am2QTH733X4xJVOYUVwWEztXarCB6+fYd64C7leGamynvn4yEkP7GZ6KvDpE/T/Yt/Rhgc3Jv2FB/NVy3phLowggMb67uW1EoCg2Y/EjKUPFTA/Bgu5Dw6Cw5cMp0mRCVQhh+JrfdLCY8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=bMz1rXDW; arc=none smtp.client-ip=185.171.202.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="bMz1rXDW" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id A6BD8C21ABF; Fri, 23 Jan 2026 14:25:30 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 607256070A; Fri, 23 Jan 2026 14:25:30 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 2E56F119A8547; Fri, 23 Jan 2026 15:25:25 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1769178329; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=Irvjef9/AWYaUeiQB1Npfq9HleYHezZV4pOTWj9W1HQ=; b=bMz1rXDWB0EDZwAIlBCY4gwkOUfUTQo1UuUvgq5q+5IlHGxlXsDxXiPaeQ9bC/9tjg+52C XcXNSzsE9TiVT/nSfy1MGqi3pPI6GuITQDBjWtbPpjOLiO7zsDFj2X4YCA+aAKEsqWG9ou SzZSq0EEuvhWMhpIpodoj+zwpyO7Vd85ihQM22HQKzENh/zc5BjvT6XYyumNrvXEMK9wt9 KPS3G9UTTDb6/kRhdz0I4K/KdcPotcgwrnwuBVa7OVfOO76nEF7yk+Y28s8CoB4xTZVK/H em6aewCHy/dJ1dN7kkOjymwPyI87eBeKi2nWHyXAJBR33s3fM1d+65ls2xdB6Q== From: =?UTF-8?B?QmVub8OudA==?= Monin To: Andy Shevchenko Cc: Andi Shyti , Mika Westerberg , Jan Dabros , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt , Thomas Petazzoni , Gregory CLEMENT , =?UTF-8?B?VGjDqW8=?= Lebrun , Tawfik Bayouk , Vladimir Kondratiev , Dmitry Guzman , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev Subject: Re: [PATCH v5 4/6] i2c: designware: Implement I2C_M_STOP support Date: Fri, 23 Jan 2026 15:25:24 +0100 Message-ID: <7226044.9J7NaK4W3v@benoit.monin> In-Reply-To: References: <20260120-i2c-dw-v5-0-0e34d6d9455c@bootlin.com> <20260120-i2c-dw-v5-4-0e34d6d9455c@bootlin.com> Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-Last-TLS-Session-Version: TLSv1.3 On Thursday, 22 January 2026 at 17:25:58 CET, Andy Shevchenko wrote: > On Tue, Jan 20, 2026 at 10:28:04AM +0100, Beno=C3=AEt Monin wrote: > > Add the support of the I2C_M_STOP flag in i2c_msg by splitting > > i2c_dw_xfer() in two: __i2c_dw_xfer_one_part() for the core transfer lo= gic > > and i2c_dw_xfer() for handling the high-level transaction management. > >=20 > > In detail __i2c_dw_xfer_one_part() starts a transaction and wait for its > > completion, either with a STOP on the bus or an error. i2c_dw_xfer() > > loops over the messages to search for the I2C_M_STOP flag and calls > > __i2c_dw_xfer_one_part() for each part of the messages up to a STOP or > > the end of the messages array. > >=20 > > i2c_dw_xfer() takes care of runtime PM and holds the hardware lock on > > the bus while calling __i2c_dw_xfer_one_part(), this allows grouping > > multiple accesses to device that support a STOP in a transaction when > > done via i2c_dev I2C_RDWR ioctl. >=20 > Does i2c-tools support this. I.o.w. can you put an example of user space = call > to achieve the above? >=20 I posted a patch series for i2c-tools, adding support for message modifier flags including I2C_M_STOP to i2ctransfer: https://lore.kernel.org/all/20251223-msg-flags-v2-0-8d934a4366e2@bootlin.co= m/ I am working on version 3, following Jean and Wolfram's reviews. [...] Thanks for the review! =2D-=20 Beno=C3=AEt Monin, Bootlin Embedded Linux and Kernel engineering https://bootlin.com