From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yong Wu Subject: Re: [PATCH v2 02/12] iommu/mediatek: Add probe_defer for smi-larb Date: Sat, 22 Jun 2019 10:42:47 +0800 Message-ID: <1561171367.4850.8.camel@mhfsdcap03> References: <1560171313-28299-1-git-send-email-yong.wu@mediatek.com> <1560171313-28299-3-git-send-email-yong.wu@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Matthias Brugger Cc: youlin.pei-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Nicolas Boichat , srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, Will Deacon , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Evan Green , Tomasz Figa , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Rob Herring , linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, yingjoe.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, anan.sun-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, Robin Murphy , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-mediatek@lists.infradead.org On Wed, 2019-06-19 at 15:52 +0200, Matthias Brugger wrote: > > On 10/06/2019 14:55, Yong Wu wrote: > > The iommu consumer should use device_link to connect with the > > smi-larb(supplier). then the smi-larb should run before the iommu > > consumer. Here we delay the iommu driver until the smi driver is > > ready, then all the iommu consumer always is after the smi driver. > > > > When there is no this patch, if some consumer drivers run before > > smi-larb, the supplier link_status is DL_DEV_NO_DRIVER(0) in the > > device_link_add, then device_links_driver_bound will use WARN_ON > > to complain that the link_status of supplier is not right. > > > > This is a preparing patch for adding device_link. > > > > Signed-off-by: Yong Wu > > --- > > drivers/iommu/mtk_iommu.c | 2 +- > > drivers/iommu/mtk_iommu_v1.c | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > > index 6fe3369..f7599d8 100644 > > --- a/drivers/iommu/mtk_iommu.c > > +++ b/drivers/iommu/mtk_iommu.c > > @@ -664,7 +664,7 @@ static int mtk_iommu_probe(struct platform_device *pdev) > > id = i; > > > > plarbdev = of_find_device_by_node(larbnode); > > - if (!plarbdev) { > > + if (!plarbdev || !plarbdev->dev.driver) { > > can't we use: > device_lock() > device_is_bound(struct device *dev) > device_unlock() A new API for me. Thanks the hint. I have tried. it is ok. > > > of_node_put(larbnode); > > return -EPROBE_DEFER; > > } > > diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c > > index 0b0908c..c43c4a0 100644 > > --- a/drivers/iommu/mtk_iommu_v1.c > > +++ b/drivers/iommu/mtk_iommu_v1.c > > @@ -604,7 +604,7 @@ static int mtk_iommu_probe(struct platform_device *pdev) > > plarbdev = of_platform_device_create( > > larb_spec.np, NULL, > > platform_bus_type.dev_root); > > - if (!plarbdev) { > > + if (!plarbdev || !plarbdev->dev.driver) { > > of_node_put(larb_spec.np); > > return -EPROBE_DEFER; > > } > >