Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752538AbaB1WC4 (ORCPT ); Fri, 28 Feb 2014 17:02:56 -0500 Received: from mail-vc0-f181.google.com ([209.85.220.181]:42121 "EHLO mail-vc0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751922AbaB1WCy (ORCPT ); Fri, 28 Feb 2014 17:02:54 -0500 MIME-Version: 1.0 In-Reply-To: <20140228215739.GA14992@kroah.com> References: <1393259343-825-1-git-send-email-mathias.nyman@linux.intel.com> <20140228203200.GE3405@xanatos> <20140228215739.GA14992@kroah.com> Date: Fri, 28 Feb 2014 14:02:53 -0800 Message-ID: Subject: Re: [RFC PATCH v2] xhci: Prevent runtime pm from autosuspending during initialization From: Dan Williams To: Greg KH Cc: Sarah Sharp , Alan Stern , Mathias Nyman , USB list , david.a.cohen@linux.intel.com, Jianqiang Tang , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 28, 2014 at 1:57 PM, Greg KH wrote: > On Fri, Feb 28, 2014 at 12:41:31PM -0800, Dan Williams wrote: >> On Fri, Feb 28, 2014 at 12:32 PM, Sarah Sharp >> wrote: >> > On Mon, Feb 24, 2014 at 12:44:46PM -0500, Alan Stern wrote: >> >> On Mon, 24 Feb 2014, Mathias Nyman wrote: >> >> >> >> > xHCI driver has its own pci probe function that will call usb_hcd_pci_probe >> >> > to register its usb-2 bus, and then continue to manually register the >> >> > usb-3 bus. usb_hcd_pci_probe does a pm_runtime_put_noidle at the end and >> >> > might thus trigger a runtime suspend before the usb-3 bus is ready. >> >> > >> >> > Prevent the runtime suspend by increasing the usage count in the >> >> > beginning of xhci_pci_probe, and decrease it once the usb-3 bus is >> >> > ready. >> >> > >> >> > xhci-platform driver is not using usb_hcd_pci_probe to set up >> >> > busses and should not need to have it's usage count increased during probe. >> >> > >> >> > Signed-off-by: Mathias Nyman >> >> > --- >> >> > drivers/usb/host/xhci-pci.c | 11 ++++++++++- >> >> > 1 file changed, 10 insertions(+), 1 deletion(-) >> >> > >> >> > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c >> >> > index 04f986d..ea7158b 100644 >> >> > --- a/drivers/usb/host/xhci-pci.c >> >> > +++ b/drivers/usb/host/xhci-pci.c >> >> > @@ -190,6 +190,10 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) >> >> > struct usb_hcd *hcd; >> >> > >> >> > driver = (struct hc_driver *)id->driver_data; >> >> > + >> >> > + /* Prevent USB-2 roothub runtime suspend until USB-3 is initialized. */ >> >> > + pm_runtime_get_noresume(&dev->dev); >> >> >> >> Strictly speaking, this prevents the _controller_ from going into >> >> runtime suspend -- not the root hub. >> > >> > Signed-off-by: Sarah Sharp >> >> Pardon the nitpick, but this is an acked-by if Mathias is submitting. > > No, it's a "chain of signed-off-by's" and this is allowed just fine (it > used to be the default-thing before we came up with the "acked-by" > line...) Ok. jejb picked on me about it once, but I'm more than willing to drop this off my list of things to nitpick. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/