From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evan Green Subject: Re: [PATCH 05/13] memory: mtk-smi: Add device-link between smi-larb and smi-common Date: Tue, 5 Mar 2019 11:02:58 -0800 Message-ID: References: <1546318276-18993-1-git-send-email-yong.wu@mediatek.com> <1546318276-18993-6-git-send-email-yong.wu@mediatek.com> <1551277985.17917.48.camel@mhfsdcap03> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <1551277985.17917.48.camel@mhfsdcap03> Sender: linux-kernel-owner@vger.kernel.org To: Yong Wu Cc: Joerg Roedel , Greg Kroah-Hartman , Matthias Brugger , Rob Herring , Robin Murphy , Tomasz Figa , Will Deacon , linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com, "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , LKML , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, Arnd Bergmann , yingjoe.chen@mediatek.com, youlin.pei@mediatek.com, Nicolas Boichat List-Id: iommu@lists.linux-foundation.org On Wed, Feb 27, 2019 at 6:33 AM Yong Wu wrote: > > On Mon, 2019-02-25 at 15:54 -0800, Evan Green wrote: > > On Mon, Dec 31, 2018 at 8:52 PM Yong Wu wrote: > > > > > > Normally, If the smi-larb HW need work, we should enable the smi-common > > > HW power and clock firstly. > > > This patch adds device-link between the smi-larb dev and the smi-common > > > dev. then If pm_runtime_get_sync(smi-larb-dev), the pm_runtime_get_sync > > > (smi-common-dev) will be called automatically. > > > > > > Since smi is built-in driver like IOMMU and never unbound, > > > DL_FLAG_AUTOREMOVE_* is not needed. > > > > > > CC: Matthias Brugger > > > Suggested-by: Tomasz Figa > > > Signed-off-by: Yong Wu > > > --- > > > drivers/memory/mtk-smi.c | 16 +++++++--------- > > > 1 file changed, 7 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c > > > index 9688341..30930e4 100644 > > > --- a/drivers/memory/mtk-smi.c > > > +++ b/drivers/memory/mtk-smi.c > > > @@ -271,6 +271,7 @@ static int mtk_smi_larb_probe(struct platform_device *pdev) > > > struct device *dev = &pdev->dev; > > > struct device_node *smi_node; > > > struct platform_device *smi_pdev; > > > + struct device_link *link; > > > > > > larb = devm_kzalloc(dev, sizeof(*larb), GFP_KERNEL); > > > if (!larb) > > > @@ -310,6 +311,12 @@ static int mtk_smi_larb_probe(struct platform_device *pdev) > > > if (!platform_get_drvdata(smi_pdev)) > > > return -EPROBE_DEFER; > > > larb->smi_common_dev = &smi_pdev->dev; > > > + link = device_link_add(dev, larb->smi_common_dev, > > > + DL_FLAG_PM_RUNTIME); > > > > Doesn't this need to be torn down in remove()? You mention that it's > > built-in and never removed, but it does seem to have a remove() > > The MTK IOMMU driver need depend on this SMI driver. the IOMMU is a > builtin driver, thus the SMI also should be a builtin driver. > > Technically, If the driver is builtin, then the "remove" function can be > removed? If yes, I could use a new patch do it. Yeah, I guess so. It's always sad to see cleanup code getting removed, but it makes sense to me. > > It looks the MACRO(builtin_platform_driver) only support one driver, but > we have two driver(smi-common and smi-larb) here. > > > function that tears down everything else, so it seemed a shame to > > start leaking now. Maybe the AUTOREMOVE flag would do it. > >