From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 916FA2D12F5; Mon, 19 Jan 2026 10:28:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768818521; cv=pass; b=UtXvCdLrgkvBc1MkgxzAhEbz086CmXXpsEBc1UwqH17xXuMr2afrbs16D833Uz9OoDJyr+Rltm4dwvJb7GN18uIyQM7AY2PqDyydaiR8ZP3uzSoE8vWwUOFgdrPLJcZe5bOwy7H37AWIogwiSahLxZBSLUUJmyUGWMyMOzI2Qck= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768818521; c=relaxed/simple; bh=UHOcM8dCH3oMm/0168Hmp5M7ehoLPJvYL3gflDB1RII=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UygcvxcjuO7F9org2GkFx0ljgN5ENG/xC1Vg06xREodxL3ilWaYOqBbb1XPcds6053OFRUHbOaBSvbsw6PHUjowSt6jtrMNHnk/miM5QQbVM9ig/di9TDlFnx0m4BhhvOr1tVmlEVSO5o67+/IU0TX8S+KXMT+Y8Er6kQ/nVutw= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=benjamin.gaignard@collabora.com header.b=IzMYIQ9x; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=benjamin.gaignard@collabora.com header.b="IzMYIQ9x" ARC-Seal: i=1; a=rsa-sha256; t=1768818497; cv=none; d=zohomail.com; s=zohoarc; b=c2+Oc9wLMk54ge9fXvqUDFJyAAT7ec7rGEzKziR5QaN+z1z+rYOLC4VTelqvmOGmxAWYdKRr6O6s6MNKpwLXDhlL5lcGObgtP0rdHil9Vb0BGdsnIs4YglM6IDmVEaxWfWUQUdSpnEvc+N1CvCq+b7wf0NJz67YVdzuQZegORwk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1768818497; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=EsuevJkgsl5C8dp30TcVS68HeqiqukUtd3I4/TFexqc=; b=PCpgNlj7n6I5+jp2Tf7Tr7dHfDi1tCAjsYDvdzMx5yFgbzZX6WT/h8sBwDUjW/hCqwYF0Ev65ozoN4kome1DuU0c3HYx8O/Q3KClOtdpMKpcdvH15iWcsAngNGweP3xIAGbiJSVfDmHKROVyhsDbXAFuGlYofF0jcARnDjD9J1M= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=benjamin.gaignard@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1768818497; s=zohomail; d=collabora.com; i=benjamin.gaignard@collabora.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:References:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=EsuevJkgsl5C8dp30TcVS68HeqiqukUtd3I4/TFexqc=; b=IzMYIQ9xcILSyPL5IEgFBFGVo7j1D7ZBB9+pLkD8TJou1OhxL5m2aeY0mUG8sBsv Wv1ahwlZ/JxKsdyJ4LI5HiTSJL64r53/U8Kqgk1RJy/0aMnZ+lBkwQr9s8a6uXe7Fe1 Ncr7UNildBZ9+LxfW3aXn6Ywt29jhDAL6JPF1W+g= Received: by mx.zohomail.com with SMTPS id 1768818497079716.4924558723245; Mon, 19 Jan 2026 02:28:17 -0800 (PST) Message-ID: Date: Mon, 19 Jan 2026 11:28:11 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 3/7] iommu: Add verisilicon IOMMU driver To: =?UTF-8?B?SsO2cmcgUsO2ZGVs?= , Will Deacon Cc: robin.murphy@arm.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, heiko@sntech.de, nicolas.dufresne@collabora.com, p.zabel@pengutronix.de, mchehab@kernel.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-media@vger.kernel.org, kernel@collabora.com References: <20260107101005.84039-1-benjamin.gaignard@collabora.com> <20260107101005.84039-4-benjamin.gaignard@collabora.com> Content-Language: en-US From: Benjamin Gaignard In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 18/01/2026 à 10:41, Jörg Rödel a écrit : > Benjamin, > > On Tue, Jan 13, 2026 at 04:10:51PM +0000, Will Deacon wrote: >> I took another look at this to see whether it had changed significantly >> from v6 when compared to the rockchip driver. Sadly, they still look >> very similar to me and I continue to suspect that the hardware is a >> derivative. I really don't understand why having a shared implementation >> of the default domain ops is difficult or controversial. Have you tried >> to write it? > When updating for v12, can you please put an explanatory comment at the top of > the file explaining the relationship of the IP this driver is for to the > RockChip IOMMU and the rationale for having it as a separate driver? I want > this part of the discussion documented in the code in case it comes up again. Does the follow wording summarize the situation correctly for you if I put it in header comment ? * This hardware block is using a 2 pages tables allocation structure. * That make very similar to Rockhip iommu hardware blocks but it has * it own driver because the registers offset and configuration bits * are completely different. An additional raison is that this hardware * has been developped by Verisilicon to be used by their hardware video * decoders and for a general purpose like Rockchip iommus. Regards, Benjamin > > > -Joerg >