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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY autolearn=ham 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 06E0EC04AAC for ; Mon, 20 May 2019 10:04:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9A802081C for ; Mon, 20 May 2019 10:04:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732323AbfETKE2 (ORCPT ); Mon, 20 May 2019 06:04:28 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:64736 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1729834AbfETKE1 (ORCPT ); Mon, 20 May 2019 06:04:27 -0400 X-UUID: 59e24c48e3944b249364089e978a8184-20190520 X-UUID: 59e24c48e3944b249364089e978a8184-20190520 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw02.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 2058970961; Mon, 20 May 2019 18:04:14 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs03n2.mediatek.inc (172.21.101.182) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 20 May 2019 18:04:13 +0800 Received: from [172.21.84.99] (172.21.84.99) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Mon, 20 May 2019 18:04:12 +0800 Message-ID: <1558346653.3318.18.camel@mtksdccf07> Subject: Re: [RFC PATCH V1 1/6] dt-bindings: mt8183: Add binding for FD shared memory From: Jerry-ch Chen To: Rob Herring CC: "hans.verkuil@cisco.com" , "laurent.pinchart+renesas@ideasonboard.com" , "tfiga@chromium.org" , "matthias.bgg@gmail.com" , "mchehab@kernel.org" , "yuzhao@chromium.org" , "zwisler@chromium.org" , "linux-mediatek@lists.infradead.org" , "linux-arm-kernel@lists.infradead.org" , Sean Cheng =?UTF-8?Q?=28=E9=84=AD=E6=98=87=E5=BC=98=29?= , "Sj Huang =?UTF-8?Q?=28=E9=BB=83=E4=BF=A1=E7=92=8B=29?=" , Christie Yu =?UTF-8?Q?=28=E6=B8=B8=E9=9B=85=E6=83=A0=29?= , Holmes Chiou =?UTF-8?Q?=28=E9=82=B1=E6=8C=BA=29?= , Frederic Chen =?UTF-8?Q?=28=E9=99=B3=E4=BF=8A=E5=85=83=29?= , Jungo Lin =?UTF-8?Q?=28=E6=9E=97=E6=98=8E=E4=BF=8A=29?= , Rynn Wu =?UTF-8?Q?=28=E5=90=B3=E8=82=B2=E6=81=A9=29?= , "linux-media@vger.kernel.org" , srv_heupstream , "devicetree@vger.kernel.org" , "shik@chromium.org" , "suleiman@chromium.org" Date: Mon, 20 May 2019 18:04:13 +0800 In-Reply-To: <20190501224512.GA4287@bogus> References: <20190423104505.38778-1-Jerry-Ch.chen@mediatek.com> <20190423104505.38778-2-Jerry-Ch.chen@mediatek.com> <20190501224512.GA4287@bogus> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-TM-SNTS-SMTP: C4BCE08F12A91F1FC96390B1BA7BC941E6507BB7E8BC193F02F220A7615273562000:8 X-MTK: N Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Rob, Thank you for your comments. On Thu, 2019-05-02 at 06:45 +0800, Rob Herring wrote: > On Tue, Apr 23, 2019 at 06:45:00PM +0800, Jerry-ch Chen wrote: > > From: Jerry-ch Chen > > > > This patch adds the binding for describing the shared memory > > used to exchange meta data between the co-processor and Face > > Detection (FD) unit of the camera system on Mediatek SoCs. > > > > Signed-off-by: Jerry-ch Chen > > --- > > .../mediatek,reserve-memory-fd_smem.txt | 44 +++++++++++++++++++ > > 1 file changed, 44 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-fd_smem.txt > > > > diff --git a/Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-fd_smem.txt b/Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-fd_smem.txt > > new file mode 100644 > > index 000000000000..52ae5071e238 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/reserved-memory/mediatek,reserve-memory-fd_smem.txt > > @@ -0,0 +1,44 @@ > > +Mediatek FD Shared Memory binding > > + > > +This binding describes the shared memory, which serves the purpose of > > +describing the shared memory region used to exchange data between Face > > +Detection hardware (FD) and co-processor in Mediatek SoCs. > > + > > +The co-processor doesn't have the iommu so we need to use the physical > > +address to access the shared buffer in the firmware. > > + > > +The Face Detection hardware (FD) can access memory through mt8183 IOMMU so > > +it can use dma address to access the memory region. > > +(See iommu/mediatek,iommu.txt for the detailed description of Mediatek IOMMU) > > + > > + > > +Required properties: > > + > > +- compatible: must be "mediatek,reserve-memory-fd_smem" > > + > > +- reg: required for static allocation (see reserved-memory.txt for > > + the detailed usage) > > + > > +- alloc-range: required for dynamic allocation. The range must > > + between 0x00000400 and 0x100000000 due to the co-processer's > > + addressing limitation > > + > > +- size: required for dynamic allocation. The unit is bytes. > > + for Face Detection Unit, you need 1 MB at least. > > What's the most? > For this part, we would like to revise as following: alloc-range: required for dynamic allocation. The range must between 0x40000000 and 0x100000000 due to the co-processor's addressing limitation size: required for dynamic allocation. The unit is bytes. for Face Detection Unit, you need 518KB. > I don't think you really need reserved memory here if you don't need a > fixed address. The size is not that big that a contiguous allocation > shouldn't be a problem (though with IOMMU you don't even need that). > 'dma-ranges' can be used to set the kernel's dma mask and ensure a > range below 0x10000000. > FD driver might be able to use the FD memory pool inside the scp reserved memory instead of declaring reserved memory here. would you have any suggestion if so? Sincerely, Jerry > Rob