Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754710AbcLNGnl (ORCPT ); Wed, 14 Dec 2016 01:43:41 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:46464 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751350AbcLNGnk (ORCPT ); Wed, 14 Dec 2016 01:43:40 -0500 Subject: Re: [PATCH v7 1/2] usb: xhci: plat: Enable runtime PM To: Baolin Wang References: <20161201214604.20717-1-robert.foss@collabora.com> <20161201214604.20717-2-robert.foss@collabora.com> Cc: mathias.nyman@intel.com, Greg KH , Julius Werner , Andrew Bresticker , Felipe Balbi , Brian Norris , LKML From: Robert Foss Message-ID: Date: Wed, 14 Dec 2016 01:43:21 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3180 Lines: 102 Hey Baolin, On 2016-12-12 12:21 AM, Baolin Wang wrote: > Hi Robert, > > On 2 December 2016 at 05:46, Robert Foss wrote: >> Enable runtime PM for the xhci-plat device so that the parent device >> may implement runtime PM. >> >> Signed-off-by: Robert Foss >> >> Tested-by: Robert Foss >> --- >> drivers/usb/host/xhci-plat.c | 29 +++++++++++++++++++++++++++-- >> 1 file changed, 27 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c >> index ed56bf9ed885..ba4efe74f537 100644 >> --- a/drivers/usb/host/xhci-plat.c >> +++ b/drivers/usb/host/xhci-plat.c >> @@ -246,6 +246,9 @@ static int xhci_plat_probe(struct platform_device *pdev) >> if (ret) >> goto dealloc_usb2_hcd; >> >> + pm_runtime_set_active(&pdev->dev); >> + pm_runtime_enable(&pdev->dev); > > You did not implement the runtime callbacks of xHCI device, then how > can the parent device control the resume/suspend of xHCI device by > runtime PM mechanism? Could you see my previous patch which implement > the runtime callbacks for xHCI device? > https://lkml.org/lkml/2016/11/28/25 > Pardon my ignorance, but which exact functions need to be implemented? Also, does the lkml link you provided contain an example implementation of those functions? >> + >> return 0; >> >> >> @@ -274,6 +277,8 @@ static int xhci_plat_remove(struct platform_device *dev) >> struct xhci_hcd *xhci = hcd_to_xhci(hcd); >> struct clk *clk = xhci->clk; >> >> + pm_runtime_disable(&dev->dev); >> + >> usb_remove_hcd(xhci->shared_hcd); >> usb_phy_shutdown(hcd->usb_phy); >> >> @@ -292,6 +297,13 @@ static int xhci_plat_suspend(struct device *dev) >> { >> struct usb_hcd *hcd = dev_get_drvdata(dev); >> struct xhci_hcd *xhci = hcd_to_xhci(hcd); >> + int ret; >> + >> + ret = pm_runtime_get_sync(dev); >> + if (ret < 0) { >> + pm_runtime_put(dev); >> + return ret; >> + } >> >> /* >> * xhci_suspend() needs `do_wakeup` to know whether host is allowed >> @@ -301,15 +313,28 @@ static int xhci_plat_suspend(struct device *dev) >> * reconsider this when xhci_plat_suspend enlarges its scope, e.g., >> * also applies to runtime suspend. >> */ >> - return xhci_suspend(xhci, device_may_wakeup(dev)); >> + ret = xhci_suspend(xhci, device_may_wakeup(dev)); >> + pm_runtime_put(dev); >> + >> + return ret; >> } >> >> static int xhci_plat_resume(struct device *dev) >> { >> struct usb_hcd *hcd = dev_get_drvdata(dev); >> struct xhci_hcd *xhci = hcd_to_xhci(hcd); >> + int ret; >> >> - return xhci_resume(xhci, 0); >> + ret = pm_runtime_get_sync(dev); >> + if (ret < 0) { >> + pm_runtime_put(dev); >> + return ret; >> + } >> + >> + ret = xhci_resume(xhci, 0); >> + pm_runtime_put(dev); >> + >> + return ret; >> } >> >> static const struct dev_pm_ops xhci_plat_pm_ops = { >> -- >> 2.11.0 >> > > >