lkml.org 
[lkml]   [2014]   [Feb]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v2] xhci: Prevent runtime pm from autosuspending during initialization
On Fri, Feb 28, 2014 at 12:41:31PM -0800, Dan Williams wrote:
> On Fri, Feb 28, 2014 at 12:32 PM, Sarah Sharp
> <sarah.a.sharp@linux.intel.com> 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 <mathias.nyman@linux.intel.com>
> >> > ---
> >> > 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 <sarah.a.sharp@linux.intel.com>
>
> 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...)


\
 
 \ /
  Last update: 2014-02-28 23:21    [W:0.040 / U:2.448 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site