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,UNPARSEABLE_RELAY,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 76A45C433E2 for ; Thu, 17 Sep 2020 10:51:16 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 11EBF204FD for ; Thu, 17 Sep 2020 10:51:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11EBF204FD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id BA07186FF0; Thu, 17 Sep 2020 10:51:15 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1rtUiMbL-J2M; Thu, 17 Sep 2020 10:51:15 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 2A20886DD5; Thu, 17 Sep 2020 10:51:15 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 05693C0864; Thu, 17 Sep 2020 10:51:15 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3C034C0051 for ; Thu, 17 Sep 2020 10:51:13 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 24270875AA for ; Thu, 17 Sep 2020 10:51:13 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id v5jZpQOUWEHc for ; Thu, 17 Sep 2020 10:51:12 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by hemlock.osuosl.org (Postfix) with ESMTPS id 0854C8757C for ; Thu, 17 Sep 2020 10:51:11 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tomeu) with ESMTPSA id 9287529BF49 Subject: Re: [PATCH 0/3] drm: panfrost: Coherency support To: Steven Price , Rob Herring , Alyssa Rosenzweig References: <20200916170409.GA2543@kevin> From: Tomeu Vizoso Message-ID: <0518e067-3b9a-8fe3-619f-8fce4c6c9677@collabora.com> Date: Thu, 17 Sep 2020 12:51:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: Neil Armstrong , Robin Murphy , dri-devel , Linux IOMMU , Kevin Hilman , "open list:ARM/Amlogic Meson..." , Will Deacon , linux-arm-kernel , Jerome Brunet 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 9/17/20 12:38 PM, Steven Price wrote: > On 16/09/2020 18:46, Rob Herring wrote: >> On Wed, Sep 16, 2020 at 11:04 AM Alyssa Rosenzweig >> wrote: >>> >>>> So I get a performance regression with the dma-coherent approach, >>>> even if it's >>>> clearly the cleaner. >>> >>> That's bizarre -- this should really be the faster of the two. >> >> Coherency may not be free. CortexA9 had something like 4x slower >> memcpy if SMP was enabled as an example. I don't know if there's >> anything going on like that specifically here. If there's never any >> CPU accesses mixed in with kmscube, then there would be no benefit to >> coherency. > > The DDK blob has the ability to mark only certain areas of memory as > coherent for performance reasons. For simple things like kmscube I would > expect that it's basically write-only from the CPU and almost all memory > the GPU touches isn't touched by the CPU. I.e. coherency isn't helping > and the coherency traffic is probably expensive. Whether the complexity > is worth it for "real" content I don't know - it may just be silly > benchmarks that benefit. Or maybe it's only a problem for applications that do silly things? I don't think kmscube was ever optimized for performance. Regards, Tomeu _______________________________________________ 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=-8.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_SANE_1 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 29BC1C43461 for ; Thu, 17 Sep 2020 10:52:43 +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 C7624204FD for ; Thu, 17 Sep 2020 10:52:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="plOPugxW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C7624204FD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com 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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=DRxUJQWTD7LlS/dxCFdhqlAGyOLe6R3L/Vccbg2uPB8=; b=plOPugxW6S5LCkjB0JZfMYf81 7c+SxOYXR9iO9cFVBCStfcA9xY1ZhDcz54b4rcRXpSop9050LbwVNBelvd1MrhY+NIF/NokXE+RmT YRDAtl0QgRTTmruTCPcezkKtNGpB6PFWWHK6F3FfrInoMUi7KRPFlSoEz2d+h3DRr3RW7fSJuj2e1 AQ+Y0LKrpUXxdhd5QHDMnTNBObo0Qj8GxYnp1ZYxFs2HAgvpaPptqvNCC3ApWABqUuAVXNVWUvbo9 v9bhS5vlobMnMAeC+B+l/0XltftOdwvbUccaoSKGZ/0iHsKqSPjblaFxY63tJcptfbqqFCfKQBYkl U90dyKnDg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIrVU-00023k-9G; Thu, 17 Sep 2020 10:51:16 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIrVP-00021L-T6; Thu, 17 Sep 2020 10:51:13 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tomeu) with ESMTPSA id 9287529BF49 Subject: Re: [PATCH 0/3] drm: panfrost: Coherency support To: Steven Price , Rob Herring , Alyssa Rosenzweig References: <20200916170409.GA2543@kevin> From: Tomeu Vizoso Message-ID: <0518e067-3b9a-8fe3-619f-8fce4c6c9677@collabora.com> Date: Thu, 17 Sep 2020 12:51:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200917_065112_080155_AA8937E6 X-CRM114-Status: GOOD ( 17.45 ) 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: Neil Armstrong , Robin Murphy , dri-devel , Linux IOMMU , Kevin Hilman , "open list:ARM/Amlogic Meson..." , Will Deacon , linux-arm-kernel , Jerome Brunet Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 9/17/20 12:38 PM, Steven Price wrote: > On 16/09/2020 18:46, Rob Herring wrote: >> On Wed, Sep 16, 2020 at 11:04 AM Alyssa Rosenzweig >> wrote: >>> >>>> So I get a performance regression with the dma-coherent approach, >>>> even if it's >>>> clearly the cleaner. >>> >>> That's bizarre -- this should really be the faster of the two. >> >> Coherency may not be free. CortexA9 had something like 4x slower >> memcpy if SMP was enabled as an example. I don't know if there's >> anything going on like that specifically here. If there's never any >> CPU accesses mixed in with kmscube, then there would be no benefit to >> coherency. > > The DDK blob has the ability to mark only certain areas of memory as > coherent for performance reasons. For simple things like kmscube I would > expect that it's basically write-only from the CPU and almost all memory > the GPU touches isn't touched by the CPU. I.e. coherency isn't helping > and the coherency traffic is probably expensive. Whether the complexity > is worth it for "real" content I don't know - it may just be silly > benchmarks that benefit. Or maybe it's only a problem for applications that do silly things? I don't think kmscube was ever optimized for performance. Regards, Tomeu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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,UNPARSEABLE_RELAY,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 53FF9C433E2 for ; Thu, 17 Sep 2020 10:51:12 +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 0CED9204FD for ; Thu, 17 Sep 2020 10:51:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0CED9204FD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.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 6ABEF6EBA4; Thu, 17 Sep 2020 10:51:11 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id BD7196EBA4 for ; Thu, 17 Sep 2020 10:51:10 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tomeu) with ESMTPSA id 9287529BF49 Subject: Re: [PATCH 0/3] drm: panfrost: Coherency support To: Steven Price , Rob Herring , Alyssa Rosenzweig References: <20200916170409.GA2543@kevin> From: Tomeu Vizoso Message-ID: <0518e067-3b9a-8fe3-619f-8fce4c6c9677@collabora.com> Date: Thu, 17 Sep 2020 12:51:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US 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: Neil Armstrong , Robin Murphy , dri-devel , Linux IOMMU , Kevin Hilman , "open list:ARM/Amlogic Meson..." , Will Deacon , linux-arm-kernel , Jerome Brunet Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 9/17/20 12:38 PM, Steven Price wrote: > On 16/09/2020 18:46, Rob Herring wrote: >> On Wed, Sep 16, 2020 at 11:04 AM Alyssa Rosenzweig >> wrote: >>> >>>> So I get a performance regression with the dma-coherent approach, >>>> even if it's >>>> clearly the cleaner. >>> >>> That's bizarre -- this should really be the faster of the two. >> >> Coherency may not be free. CortexA9 had something like 4x slower >> memcpy if SMP was enabled as an example. I don't know if there's >> anything going on like that specifically here. If there's never any >> CPU accesses mixed in with kmscube, then there would be no benefit to >> coherency. > > The DDK blob has the ability to mark only certain areas of memory as > coherent for performance reasons. For simple things like kmscube I would > expect that it's basically write-only from the CPU and almost all memory > the GPU touches isn't touched by the CPU. I.e. coherency isn't helping > and the coherency traffic is probably expensive. Whether the complexity > is worth it for "real" content I don't know - it may just be silly > benchmarks that benefit. Or maybe it's only a problem for applications that do silly things? I don't think kmscube was ever optimized for performance. Regards, Tomeu _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel 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=-8.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_SANE_1 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 49A5FC43461 for ; Thu, 17 Sep 2020 10:51:23 +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 D4FE2204FD for ; Thu, 17 Sep 2020 10:51:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="PYBJrZ2A" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D4FE2204FD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-amlogic-bounces+linux-amlogic=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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5Z/pp36vy5GWBEcT+YfRr4lqmNHqBRhZSntQNtzUjoA=; b=PYBJrZ2AqqtSMh74uBAByxBoi S2wP6X9IZSWF3/+agSrhTL9SJgF8boU5J0AYfieF0MKFYByfIy5J1Lv4+QMZ+bNHxIVApiUvXbUKH J2FJNdV5mEhhTHeQCScGea7omQxoHtcoCbLV0UCuqLamq/YwU6wmmlYWxRcVywYfLPAn+fdfGd3XJ 5oRHSYRK3J8nj0SYyJ3QgNBE2gqpm0a3ArlnTLQxAOJzAsCCIx8NvvqV3Cg53IgqyROEBpoI0qyRa WXuDFNk0G/OhLMlW4dxs8n4gZJJYheLuvNNVR2yLug3+xI5w5LCF3YIxb2uH9m2I64YG/PJEqvn9r Pi2jBj2Dw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIrVT-00023L-4N; Thu, 17 Sep 2020 10:51:15 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIrVP-00021L-T6; Thu, 17 Sep 2020 10:51:13 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tomeu) with ESMTPSA id 9287529BF49 Subject: Re: [PATCH 0/3] drm: panfrost: Coherency support To: Steven Price , Rob Herring , Alyssa Rosenzweig References: <20200916170409.GA2543@kevin> From: Tomeu Vizoso Message-ID: <0518e067-3b9a-8fe3-619f-8fce4c6c9677@collabora.com> Date: Thu, 17 Sep 2020 12:51:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200917_065112_080155_AA8937E6 X-CRM114-Status: GOOD ( 17.45 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Neil Armstrong , Robin Murphy , dri-devel , Linux IOMMU , Kevin Hilman , "open list:ARM/Amlogic Meson..." , Will Deacon , linux-arm-kernel , Jerome Brunet Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org On 9/17/20 12:38 PM, Steven Price wrote: > On 16/09/2020 18:46, Rob Herring wrote: >> On Wed, Sep 16, 2020 at 11:04 AM Alyssa Rosenzweig >> wrote: >>> >>>> So I get a performance regression with the dma-coherent approach, >>>> even if it's >>>> clearly the cleaner. >>> >>> That's bizarre -- this should really be the faster of the two. >> >> Coherency may not be free. CortexA9 had something like 4x slower >> memcpy if SMP was enabled as an example. I don't know if there's >> anything going on like that specifically here. If there's never any >> CPU accesses mixed in with kmscube, then there would be no benefit to >> coherency. > > The DDK blob has the ability to mark only certain areas of memory as > coherent for performance reasons. For simple things like kmscube I would > expect that it's basically write-only from the CPU and almost all memory > the GPU touches isn't touched by the CPU. I.e. coherency isn't helping > and the coherency traffic is probably expensive. Whether the complexity > is worth it for "real" content I don't know - it may just be silly > benchmarks that benefit. Or maybe it's only a problem for applications that do silly things? I don't think kmscube was ever optimized for performance. Regards, Tomeu _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic