From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (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 3A292346AE3; Wed, 10 Jun 2026 18:51:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781117497; cv=none; b=FI+/U9jxP3TbfN1InPoSB4QoQgJqyr4Pa2QvvtK7bFs3cZtgFMrOvqTJ0a4dedWxKzX10m1HFOHFjc0W1NXPoznq9mGOyfhHtbd1nigyS0llMHmEgxIbJfAW1fdB7xA+CL60lCovaAbmEyygAHSNoFvLoiFgoU8yMKCzZHuCeLY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781117497; c=relaxed/simple; bh=IAJeaJCSOrokeJqsoh7ZMS5JEDntzqitc8aG5X9uM6A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VW4n48saM8n31LoJ/zJdSz89rL4u5z7BsaxbVk7m2XTdfmMl51cqFZ8nMJ1VdIJNgOl7dmVrVcBNrj4B8f3gQvsCXg54vI87fASPceEKKI7BPSLaQMLT7L4R4PFYX41+0d3MEVcB9ctqvyffeT7sHj0PoYfopsrsOrasLAgouAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=aye66uGD; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="aye66uGD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1781117496; x=1812653496; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=IAJeaJCSOrokeJqsoh7ZMS5JEDntzqitc8aG5X9uM6A=; b=aye66uGDZKdQa9WjHMvX9ETjKqfTUZgBFSSA0Bq5xxh5lzQAfK+g2BqH LAU0myHxq65Fo0sCMoTh7EZ4yMDs7hhfZQ2jxn42oSfgCFgmotgjyyiNf BPsP1dCs0bt1oevZytmakFJebNOlM1SObYjyqOB60q30Gk96MG7A4J6R3 M26/9n/89fyX5FywxFTLCUC48dG2L/9dD7Ymt/ocgDY24uvrh0B1sxKn1 +2DxP4/VM1Jt9NLVafPLnBffLumN67z4JKgW85x0uecoAknFlfx0IHyoT 05myRlxrMGUf3W2rN/UMKBmJuIY4Txt5X5CxqWeSmOMJ1Ysb99rdAOn03 Q==; X-CSE-ConnectionGUID: lBddJ2uWRcyl589jQROy0Q== X-CSE-MsgGUID: SG/qs1cmS4633UOA0NuT9Q== X-IronPort-AV: E=McAfee;i="6800,10657,11813"; a="81054028" X-IronPort-AV: E=Sophos;i="6.24,197,1774335600"; d="scan'208";a="81054028" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2026 11:51:35 -0700 X-CSE-ConnectionGUID: Ld7552xLQuatmRnoelVB+w== X-CSE-MsgGUID: 6f666/mdTJOs8w9zQz3/bA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,197,1774335600"; d="scan'208";a="245385735" Received: from hrotuna-mobl2.ger.corp.intel.com (HELO localhost) ([10.245.244.38]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2026 11:51:30 -0700 Date: Wed, 10 Jun 2026 21:51:27 +0300 From: Andy Shevchenko To: Svyatoslav Ryhel Cc: Lee Jones , Daniel Thompson , Jingoo Han , Pavel Machek , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Cameron , David Lechner , Nuno =?iso-8859-1?Q?S=E1?= , Andy Shevchenko , Helge Deller , Johan Hovold , dri-devel@lists.freedesktop.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, linux-fbdev@vger.kernel.org Subject: Re: [PATCH v4 10/14] mfd: lm3533: Set DMA mask Message-ID: References: <20260606045738.21050-1-clamor95@gmail.com> <20260606045738.21050-11-clamor95@gmail.com> Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Wed, Jun 10, 2026 at 05:40:56PM +0300, Svyatoslav Ryhel wrote: > вт, 9 черв. 2026 р. о 22:17 Andy Shevchenko пише: > > On Sat, Jun 06, 2026 at 07:57:34AM +0300, Svyatoslav Ryhel wrote: > > > Missing coherent_dma_mask assigning triggers the following warning in > > > dmesg: > > > > > > [ 3.287872] platform lm3533-backlight.0: DMA mask not set > > > > > > Since this warning might be elevated to an error in the future, set > > > coherent_dma_mask to zero because both the core and cells do not utilize > > > DMA. > > > > Hmm... I am not sure about this. The entire kernel has only two drivers that > > do that, and thanks to their commit messages one of them pointed out to the > > commit from 2018. So, if no other devices suffer from this, I think it has to > > be a better way of achieving the same. > > If mfd framework warns that DMA mask is not set then this must be > addressed. Why then there is such warning at the first place if mask > can be just skipped. Then warning would be just a debug message. What > is warning today can become error tomorrow. It's there for 8 years. And only a few drivers explicitly nullify it. I think doing this patch one should really understand what's going on. (Note, I'm not that person, it's my gut feelings based on the experience and the above statistics.) MFD creates a lot of platform devices for which DMA mask is set automatically. So, why is it not set properly for this device? -- With Best Regards, Andy Shevchenko