From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D822C433B4 for ; Mon, 17 May 2021 16:35:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 410B2611BF for ; Mon, 17 May 2021 16:35:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243067AbhEQQg5 (ORCPT ); Mon, 17 May 2021 12:36:57 -0400 Received: from foss.arm.com ([217.140.110.172]:57760 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244641AbhEQQgr (ORCPT ); Mon, 17 May 2021 12:36:47 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EEA2C106F; Mon, 17 May 2021 09:35:30 -0700 (PDT) Received: from [10.57.66.179] (unknown [10.57.66.179]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D8D063F73D; Mon, 17 May 2021 09:35:28 -0700 (PDT) Subject: Re: [PATCH v5 4/6] drm/sprd: add Unisoc's drm display controller driver To: Joerg Roedel , Kevin Tang Cc: Maxime Ripard , Maarten Lankhorst , Sean Paul , David Airlie , Daniel Vetter , Rob Herring , Mark Rutland , Orson Zhai , Chunyan Zhang , "Linux-Kernel@Vger. Kernel. Org" , ML dri-devel , devicetree@vger.kernel.org References: <20210425123607.26537-1-kevin3.tang@gmail.com> <20210425123607.26537-5-kevin3.tang@gmail.com> <20210430092249.n75to2das5m6p4zb@gilmour> From: Robin Murphy Message-ID: Date: Mon, 17 May 2021 17:35:23 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-05-17 10:27, Joerg Roedel wrote: > On Fri, Apr 30, 2021 at 08:20:10PM +0800, Kevin Tang wrote: >> Cc Robin & Joerg > > This is just some GPU internal MMU being used here, it seems. It doesn't > use the IOMMU core code, so no Ack needed from the IOMMU side. Except the actual MMU being used is drivers/iommu/sprd_iommu.c - this is just the display driver poking directly at the interrupt registers of its associated IOMMU instance. I still think this is wrong, and that it should be treated as a shared interrupt, with the IOMMU driver handling its own registers and reporting to the client through the standard report_iommu_fault() API, especially since there are apparently more blocks using these IOMMU instances than just the display. Robin. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D7EAC433B4 for ; Mon, 17 May 2021 16:35:35 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D7904611B0 for ; Mon, 17 May 2021 16:35:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D7904611B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2F4556E7EF; Mon, 17 May 2021 16:35:34 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id CCB0E6E7EF for ; Mon, 17 May 2021 16:35:31 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EEA2C106F; Mon, 17 May 2021 09:35:30 -0700 (PDT) Received: from [10.57.66.179] (unknown [10.57.66.179]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D8D063F73D; Mon, 17 May 2021 09:35:28 -0700 (PDT) Subject: Re: [PATCH v5 4/6] drm/sprd: add Unisoc's drm display controller driver To: Joerg Roedel , Kevin Tang References: <20210425123607.26537-1-kevin3.tang@gmail.com> <20210425123607.26537-5-kevin3.tang@gmail.com> <20210430092249.n75to2das5m6p4zb@gilmour> From: Robin Murphy Message-ID: Date: Mon, 17 May 2021 17:35:23 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, David Airlie , Chunyan Zhang , "Linux-Kernel@Vger. Kernel. Org" , ML dri-devel , Rob Herring , Maxime Ripard , Orson Zhai , Sean Paul Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 2021-05-17 10:27, Joerg Roedel wrote: > On Fri, Apr 30, 2021 at 08:20:10PM +0800, Kevin Tang wrote: >> Cc Robin & Joerg > > This is just some GPU internal MMU being used here, it seems. It doesn't > use the IOMMU core code, so no Ack needed from the IOMMU side. Except the actual MMU being used is drivers/iommu/sprd_iommu.c - this is just the display driver poking directly at the interrupt registers of its associated IOMMU instance. I still think this is wrong, and that it should be treated as a shared interrupt, with the IOMMU driver handling its own registers and reporting to the client through the standard report_iommu_fault() API, especially since there are apparently more blocks using these IOMMU instances than just the display. Robin.