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 399F82E92D4 for ; Thu, 26 Feb 2026 20:25:44 +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=1772137546; cv=none; b=s5Qu63g7PUFT0oYNHF+/Xe1N7zEJOy9SL9jvOxwsKBFgC/MNFGv8fsU7HZJ5nsG2rZSEAfsgDPg84R+kl2dnL6PAfArYd0s8s5e+gYDtk1ZaZvi3nk5KaNHk0Wnz3tTYx22lFV2icXZn64YXVwDfgYuu6EWePRj0o1eaJnqC93M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772137546; c=relaxed/simple; bh=yVRIge80aimtKsnkGLeGz6lSpxDwFQm93O/qmf8x+8o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=laLznIMrRZAqIPX6mCBtF3NqtFo3RYqEXHTx5Gg+z9JhPzXUIAAxcSOoKoHK6/Ip+lDBeq4DDlue5v7EfpXazDDp/36AMZXUy+VWj1O8pSWKflu8RrzSyqHFDQ1Rl8zb+ArTIM+QA3OOKX+FC08tyjlWZvDd7eQnuh9C83iqyKs= 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=eMg7+MtH; 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="eMg7+MtH" 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=Sh/s 3qFva466wglan6cTKI7jr/g9T3NqxFeeJ0K5Yn4=; b=eMg7+MtHs+JE+Ztk+rzN VSY/ldpbERoaSSIuYIUZSMCBmangRnBH8sGrk/8juZeBVaFQZ1QozPy0C175ad4j x7ypHFYbRbbX5mjfnqcNFhEgPpKfo556mDuQVHvmxuFcUbpevonMjOvuQ1VSjnpN SCnf704z3qXjkQj7PlMQjtDZRVw9r4dI1Yptj8XMzS8sgv1+MQb0Iha2yNMmnHJZ 8EJaD7obXcg1j+A7x4Oi+8T6PpesKcXCLBiXEmGfTrqo3Ea6griUHvkFd+8MntTr ifLWvoo80DXPje+0DWRLh9Y9HmqZoK5oNu5325kVXPDGBbsz4vXjT1d7aEtKfV6D IA== Received: (qmail 1210745 invoked from network); 26 Feb 2026 21:25:43 +0100 Received: by mail.zeus03.de with UTF8SMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 26 Feb 2026 21:25:43 +0100 X-UD-Smtp-Session: l3s3148p1@SWC87L9L9JAujnuU Date: Thu, 26 Feb 2026 21:25:42 +0100 From: Wolfram Sang To: Bartosz Golaszewski Cc: Mika Westerberg , Andy Shevchenko , Jan Dabros , Andi Shyti , Lixu Zhang , Sakari Ailus , Binbin Zhou , Fabrizio Castro , Israel Cepeda , Hans de Goede , Nirujogi Pratap , Bin Du , Hans Hu , Bartosz Golaszewski , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH v2 0/9] i2c: provide and use i2c_adapter_set_node() Message-ID: References: <20260223-i2c-ada-dev-set-node-v2-0-77018c536610@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260223-i2c-ada-dev-set-node-v2-0-77018c536610@oss.qualcomm.com> On Mon, Feb 23, 2026 at 10:08:18AM +0100, Bartosz Golaszewski wrote: > It's been another year of discussing the object life-time problems at > conferences. I2C is one of the offenders and its problems are more > complex than those of some other subsystems. It seems the revocable[1] > API may make its way into the kernel this year but even with it in > place, I2C won't be able to use it as there's currently nothing to > *revoke*. The struct device is embedded within the i2c_adapter struct > whose lifetime is tied to the provider device being bound to its driver. > > Fixing this won't be fast and easy but nothing's going to happen if we > don't start chipping away at it. The ultimate goal in order to be able > to use an SRCU-based solution (revocable or otherwise) is to convert the > embedded struct device in struct i2c_adapter into an __rcu pointer that > can be *revoked*. To that end we need to hide all dereferences of > adap->dev in drivers. > > I2C drivers use device_set_node() to assign a firmware node directly to > the struct device embedded in i2c_adapter. In order to hide the direct > dereferencing: provide a dedicated interface that wraps the call to > device_set_node() but takes the adapter as argument instead. > > Link: https://lore.kernel.org/all/20251106152330.11733-1-tzungbi@kernel.org/ > Signed-off-by: Bartosz Golaszewski Applied to for-current, squashed... > --- > Changes in v2: > - add patches replacing ACPI_COMPANION_SET() with i2c_adapter_set_node() > - rebased on top of v7.0-rc1 ... and resolved another merge conflict :/ But despite this minor hickup, thanks a ton for your work! Looking forward to your follow-up patches. Happy hacking!