From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 9B286433D1 for ; Thu, 3 Apr 2025 14:19:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743689969; cv=none; b=N+I5wMQCZOI1cB0Dr/whywLR4xvC69MftyqBT2luUwR3Kpyt0kAFyuULDIO0VNIpYnVD3C/R99PjYfvvrD4Ypyf0vYoqoT5OVE7/NCzg1uVgOfmvtsJT4XUmZBuxJgDMTj5h3d3HU5x5QHv5id6ZRZPvg1mpbXXYekP/HEDoSlY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743689969; c=relaxed/simple; bh=hIxZ8DXbteEySXel5MzoSaZF1xDhFewUBhiOqfvIxLM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MO9ez3zcp9MJlPe+7M6PzSIpcVGb9WivkYyoJYbZWNA4+KotpovRdCGHDiSRhRRxk6G+fVIGsWq5IyEtjS4ntA/QqxKcXK0dq2PtMkixcF9Z713x8QwlqvemU06RJOqjda6W4vTmIWRcVsmXkwmKYf5youQm2i2lDhVqxrb29IU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=IqmfwKh6; arc=none smtp.client-ip=192.198.163.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="IqmfwKh6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1743689968; x=1775225968; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=hIxZ8DXbteEySXel5MzoSaZF1xDhFewUBhiOqfvIxLM=; b=IqmfwKh6Ujxtofr4tFP071C/eU+nrPUa7WICD4cJbFHqUx3GBwbIAGuH h9hc4Ttk53vkU8v6xnolMkR83Kl/jVciIiM4UQLigbebRzx1GgyBkjha4 Sb7ZKuny4EktLMMjJ5GbV8JPui7JR6F1HcZIO79EO07vHdwJOdEzvA8f7 KaXXM9SBnqnIWSiC3V/xqQetAhAiEOwIjKaHPm6fQvmLjDQaSQRkQlgSV C1mfe0KOr7KttW1/kRZ1m0RFVkKjIyYgeMP9OUrTgXTPJFkAv+/u/wyFf HrlQOZAVeYigrvU0KoJSMx4flHDbckUH73A1YNOFYkEceUqvQImifyBB2 g==; X-CSE-ConnectionGUID: PL3wTvyQTS2Gn+k7vw+TLA== X-CSE-MsgGUID: oDcTxToUT1aGC4QhQpXTNQ== X-IronPort-AV: E=McAfee;i="6700,10204,11393"; a="70471409" X-IronPort-AV: E=Sophos;i="6.15,184,1739865600"; d="scan'208";a="70471409" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Apr 2025 07:19:27 -0700 X-CSE-ConnectionGUID: WGTUO9I3RJugZ+moxd3ysw== X-CSE-MsgGUID: dCuTS7AVQsOL+p23m/gdfg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,184,1739865600"; d="scan'208";a="127306515" Received: from smile.fi.intel.com ([10.237.72.58]) by fmviesa008.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Apr 2025 07:19:25 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.98.2) (envelope-from ) id 1u0LPf-00000008prL-0ejI; Thu, 03 Apr 2025 17:19:23 +0300 Date: Thu, 3 Apr 2025 17:19:22 +0300 From: Andy Shevchenko To: Greg KH Cc: Raag Jadav , david.m.ertman@intel.com, ira.weiny@intel.com, lee@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] mfd: core: Support auxiliary device Message-ID: References: <20250403110053.1274521-1-raag.jadav@intel.com> <2025040336-ethically-regulate-3594@gregkh> 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: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo On Thu, Apr 03, 2025 at 05:16:51PM +0300, Andy Shevchenko wrote: > On Thu, Apr 03, 2025 at 03:02:47PM +0100, Greg KH wrote: > > On Thu, Apr 03, 2025 at 04:30:53PM +0530, Raag Jadav wrote: ... > > > 2. Should we allow auxiliary drivers to manage their own resources > > > (MEM, IO, IRQ etc)? > > > > The resources are all shared by the "parent" device, that's what makes > > aux drivers work, they need to handle this as there is no unique way to > > carve up the resources here. > > > > So I don't know how you would do this, sorry. > > I think we should simply enforce the requirement that MFD on AUX bus must use > regmap. This will solve the serialisation and common access to the resources. That said, make an additional API call like dev_mfd_add_aux_devices() which should enforce new infrastructure and convert drivers one by one. Also with that you may add a warning to the existing (PCI) drivers that are using old API if (dev_is_pci(parent)) dev_warn(parent, "Uses old API, please switch to ...\n"); -- With Best Regards, Andy Shevchenko