From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932827AbdELPFe (ORCPT ); Fri, 12 May 2017 11:05:34 -0400 Received: from mail-wr0-f195.google.com ([209.85.128.195]:33365 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932315AbdELPFb (ORCPT ); Fri, 12 May 2017 11:05:31 -0400 Subject: Re: [PATCH v3 3/3] media: mtk-mdp: Fix mdp device tree To: Minghsiu Tsai , Hans Verkuil , daniel.thompson@linaro.org, Rob Herring , Mauro Carvalho Chehab , Daniel Kurtz , Pawel Osciak , Houlong Wei Cc: srv_heupstream@mediatek.com, Eddie Huang , Yingjoe Chen , Wu-Cheng Li , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-mediatek@lists.infradead.org References: <1494559361-42835-1-git-send-email-minghsiu.tsai@mediatek.com> <1494559361-42835-4-git-send-email-minghsiu.tsai@mediatek.com> From: Matthias Brugger Message-ID: <60f89b9a-f068-25a7-3f8b-d13b19357361@gmail.com> Date: Fri, 12 May 2017 17:05:27 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <1494559361-42835-4-git-send-email-minghsiu.tsai@mediatek.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/05/17 05:22, Minghsiu Tsai wrote: > From: Daniel Kurtz > > If the mdp_* nodes are under an mdp sub-node, their corresponding > platform device does not automatically get its iommu assigned properly. > > Fix this by moving the mdp component nodes up a level such that they are > siblings of mdp and all other SoC subsystems. This also simplifies the > device tree. > > Although it fixes iommu assignment issue, it also break compatibility > with old device tree. So, the patch in driver is needed to iterate over > sibling mdp device nodes, not child ones, to keep driver work properly. > Couldn't we preserve backwards compatibility by doing something like this: diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c index 9e4eb7dcc424..277d8fe6eb76 100644 --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c @@ -103,7 +103,7 @@ static int mtk_mdp_probe(struct platform_device *pdev) { struct mtk_mdp_dev *mdp; struct device *dev = &pdev->dev; - struct device_node *node; + struct device_node *node, *parent; int i, ret = 0; mdp = devm_kzalloc(dev, sizeof(*mdp), GFP_KERNEL); @@ -117,8 +117,14 @@ static int mtk_mdp_probe(struct platform_device *pdev) mutex_init(&mdp->lock); mutex_init(&mdp->vpulock); + /* Old dts had the components as child nodes */ + if (of_get_next_child(dev->of_node, NULL)) + parent = dev->of_node; + else + parent = dev->of_node->parent; + /* Iterate over sibling MDP function blocks */ - for_each_child_of_node(dev->of_node, node) { + for_each_child_of_node(parent, node) { const struct of_device_id *of_id; enum mtk_mdp_comp_type comp_type; int comp_id; Maybe even by putting a warning in the if branch to make sure, people are aware of their out-of-date device tree blobs. Regards, Matthias > Signed-off-by: Daniel Kurtz > Signed-off-by: Minghsiu Tsai > > --- > drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c > index 9e4eb7d..a5ad586 100644 > --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c > +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c > @@ -118,7 +118,7 @@ static int mtk_mdp_probe(struct platform_device *pdev) > mutex_init(&mdp->vpulock); > > /* Iterate over sibling MDP function blocks */ > - for_each_child_of_node(dev->of_node, node) { > + for_each_child_of_node(dev->of_node->parent, node) { > const struct of_device_id *of_id; > enum mtk_mdp_comp_type comp_type; > int comp_id; >