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=-5.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 7E1FFC433E1 for ; Wed, 19 Aug 2020 13:56:02 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (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 EBB562075E for ; Wed, 19 Aug 2020 13:56:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="t9dg9W+L" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EBB562075E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 66E0E1847; Wed, 19 Aug 2020 15:55:10 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 66E0E1847 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1597845360; bh=G724kSAuscCEKcE+1I5WprrlD58qapouUROYmUhMhl4=; h=Date:From:To:Subject:References:In-Reply-To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=t9dg9W+LUZo/q0Xx1G330WNvolaxrIozuTsMCbwLTFzLB5RwK9gXSnGghftO5M9gi fyU6/a081aLQVJeP0SKN8Be769aGcTOKgMf9euA11TDE7YjwHDDn01BLw3JeESxhiR /tvJE8NJP4Z+5jRDaFj2opUUL9PSsqRtt6k+zgz4= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id EF933F80216; Wed, 19 Aug 2020 15:55:09 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 02738F80218; Wed, 19 Aug 2020 15:55:08 +0200 (CEST) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id CF7E2F80114 for ; Wed, 19 Aug 2020 15:54:57 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz CF7E2F80114 Received: by verein.lst.de (Postfix, from userid 2407) id 8062B68BEB; Wed, 19 Aug 2020 15:54:55 +0200 (CEST) Date: Wed, 19 Aug 2020 15:54:55 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200819135454.GA17098@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , Marek Szyprowski , linux-samsung-soc , Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers. 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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 B0003C433DF for ; Wed, 19 Aug 2020 13:55:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FA5E204FD for ; Wed, 19 Aug 2020 13:55:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728555AbgHSNzB (ORCPT ); Wed, 19 Aug 2020 09:55:01 -0400 Received: from verein.lst.de ([213.95.11.211]:37889 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726961AbgHSNzB (ORCPT ); Wed, 19 Aug 2020 09:55:01 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 8062B68BEB; Wed, 19 Aug 2020 15:54:55 +0200 (CEST) Date: Wed, 19 Aug 2020 15:54:55 +0200 From: Christoph Hellwig To: Tomasz Figa Cc: Christoph Hellwig , Mauro Carvalho Chehab , Thomas Bogendoerfer , "James E.J. Bottomley" , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Ben Skeggs , Pawel Osciak , Marek Szyprowski , Matt Porter , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Tom Lendacky , alsa-devel@alsa-project.org, linux-samsung-soc , linux-ia64@vger.kernel.org, linux-scsi@vger.kernel.org, linux-parisc@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, Linux Kernel Mailing List , linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Linux Media Mailing List Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200819135454.GA17098@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Wed, 19 Aug 2020 13:54:55 +0000 Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-Id: <20200819135454.GA17098@lst.de> List-Id: References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tomasz Figa Cc: Christoph Hellwig , Mauro Carvalho Chehab , Thomas Bogendoerfer , "James E.J. Bottomley" , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Ben Skeggs , Pawel Osciak , Marek Szyprowski , Matt Porter , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Tom Lendacky , alsa-devel@alsa-project.org, linux-samsung-soc , linux-ia64@vger.kernel.org, linux-scsi@vger.kernel.org, linux-parisc@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, Linux Kernel Mailing List , linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Linux Media Mailing List On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers. 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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 3274EC433E4 for ; Wed, 19 Aug 2020 13:55:05 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 066F82075E for ; Wed, 19 Aug 2020 13:55:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 066F82075E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id D399C861F4; Wed, 19 Aug 2020 13:55:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NthCodjNEZiK; Wed, 19 Aug 2020 13:55:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 9E2E985700; Wed, 19 Aug 2020 13:55:03 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 81312C0889; Wed, 19 Aug 2020 13:55:03 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6D538C0051 for ; Wed, 19 Aug 2020 13:55:02 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 59C0A85700 for ; Wed, 19 Aug 2020 13:55:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id EiazjIbbfJ3d for ; Wed, 19 Aug 2020 13:55:01 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by whitealder.osuosl.org (Postfix) with ESMTPS id E72EB861E7 for ; Wed, 19 Aug 2020 13:55:00 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 8062B68BEB; Wed, 19 Aug 2020 15:54:55 +0200 (CEST) Date: Wed, 19 Aug 2020 15:54:55 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200819135454.GA17098@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , linux-samsung-soc , Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 04D4AC433DF for ; Wed, 19 Aug 2020 13:55:14 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 C7C762076E for ; Wed, 19 Aug 2020 13:55:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="k2M538cP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C7C762076E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=y1B8dnfxhVWabuVHwwOd4wuweKznyTki0L3XehLGKnI=; b=k2M538cPskFvguLtplWPBHpMH Zjw1AtccVuQqDWxdutHPzGaQ0heFB4t8AqQGPK+24en/UYNxZq/HgtyzXzGwy9qXmRI+zBzZOXRO2 DXTsKYoEDriuZrkSDuIU13yLmDrSEsv3wcW3lduooo9TpJippCw5pEZPyJbaD50vUo5jdNB4HiIpi eEM/p0Oq0QTGsX2aoOSvq1+PqMEOcx3OtqfpIhjPvPWo72eS+I6m5O+TuQAIbvfl0v72rilecJlYA OphJ0bJ8jErjwt4BZc3qt3RAhufY7MrPX1A3o/2JDVmdhbaGF/2Lu71209fNqVPYtWfF3agYMJwEG Cr0TuGAlA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8OYV-0006tq-Ix; Wed, 19 Aug 2020 13:55:07 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8OYP-0006rD-JR; Wed, 19 Aug 2020 13:55:03 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 8062B68BEB; Wed, 19 Aug 2020 15:54:55 +0200 (CEST) Date: Wed, 19 Aug 2020 15:54:55 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200819135454.GA17098@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200819_095501_780242_08C919D2 X-CRM114-Status: GOOD ( 15.49 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , Marek Szyprowski , linux-samsung-soc , Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Date: Wed, 19 Aug 2020 15:54:55 +0200 Message-ID: <20200819135454.GA17098@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-ia64-owner@vger.kernel.org To: Tomasz Figa Cc: Christoph Hellwig , Mauro Carvalho Chehab , Thomas Bogendoerfer , "James E.J. Bottomley" , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Ben Skeggs , Pawel Osciak , Marek Szyprowski , Matt Porter , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Tom Lendacky , alsa-devel@alsa-project.org, linux-samsung-soc , linux-ia64@vger.kernel.org, linux-scsi@vger List-Id: nouveau.vger.kernel.org On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers. 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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 54748C433DF for ; Wed, 19 Aug 2020 13:56:26 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 1A954204FD for ; Wed, 19 Aug 2020 13:56:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="2oFjkDLj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A954204FD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=HicLQ9glJ824Q7hAQ3D1UdiOB06fhkP2qhAwLZwNgTE=; b=2oFjkDLjJtQU3G+dNViTjUGKJ 9/7z3PxFh5Ztxe5HO4u7X6QzVqHpQvYO9x5NEOmGnbA43fdqZUm95kKQ7Fdept+MqPMPadAMY4+o6 62JCw9gjuDX1IQmJV7BFCfQzMf3XoaSkZe9riJ/oOw+7NalfhbCUsba1PXesUhRxq8DEsz2la0Nzx fJ/b2X/XIdmAsewBTW7S5fXmcrjaZ5Z1xctHW4wFFor3IOys1hUrP8zpFMmKSgHCOyi/GXe+x7+/0 I8WemGIg+2vlZcyXr5abWTnpiVKMg72KImeMtJxEoaTelVz6H2NR8CE6XgCGF9FUWpXOzP4OoxLeE hYsYkLbow==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8OYS-0006sn-LR; Wed, 19 Aug 2020 13:55:04 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8OYP-0006rD-JR; Wed, 19 Aug 2020 13:55:03 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 8062B68BEB; Wed, 19 Aug 2020 15:54:55 +0200 (CEST) Date: Wed, 19 Aug 2020 15:54:55 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200819135454.GA17098@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200819_095501_780242_08C919D2 X-CRM114-Status: GOOD ( 15.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , Marek Szyprowski , linux-samsung-soc , Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Aug 19, 2020 at 01:16:51PM +0200, Tomasz Figa wrote: > Hi Christoph, > > On Wed, Aug 19, 2020 at 8:56 AM Christoph Hellwig wrote: > > > > The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, > > Could you explain what makes you think it's unused? It's a feature of > the UAPI generally supported by the videobuf2 framework and relied on > by Chromium OS to get any kind of reasonable performance when > accessing V4L2 buffers in the userspace. Because it doesn't do anything except on PARISC and non-coherent MIPS, so by definition it isn't used by any of these media drivers. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel