lkml.org 
[lkml]   [2020]   [Apr]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: lockdep warning in urb.c:363 usb_submit_urb
    On 04/20/20 16:26, Alan Stern wrote:
    > On Wed, 25 Mar 2020, Alan Stern wrote:
    >
    > > On Wed, 25 Mar 2020, Qais Yousef wrote:
    > >
    > > > Thanks for all the hints Alan.
    > > >
    > > > I think I figured it out, the below patch seems to fix it for me. Looking
    > > > at other drivers resume functions it seems we're missing the
    > > > pm_runtime_disable()->set_active()->enable() dance. Doing that fixes the
    > > > warning and the dev_err() in driver/base/power.
    > >
    > > Ah, yes. This should have been added years ago; guess I forgot. :-(
    > >
    > > > I don't see xhci-plat.c doing that, I wonder if it needs it too.
    > > >
    > > > I'm not well versed about the details and the rules here. So my fix could be
    > > > a hack, though it does seem the right thing to do.
    > > >
    > > > I wonder why the power core doesn't handle this transparently..
    > >
    > > Initially, we didn't want the PM core to do this automatically because
    > > we thought some devices might want to remain runtime-suspended
    > > following a system resume, and only the device driver would know what
    > > to do.
    >
    > Qais:
    >
    > So it looks like the discussion with Rafael will lead to changes in the
    > PM core, but they won't go into the -stable kernels, and they won't
    > directly fix the problem here.
    >
    > In the meantime, why don't you write up your patch below and submit it
    > properly? Even better, create similar patches for ehci-platform.c and
    > xhci-plat.c and submit them too.

    Sure.

    Thanks

    --
    Qais Yousef

    >
    > Alan Stern
    >
    > > > diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
    > > > index 7addfc2cbadc..eb92c8092fae 100644
    > > > --- a/drivers/usb/host/ohci-platform.c
    > > > +++ b/drivers/usb/host/ohci-platform.c
    > > > @@ -299,6 +299,10 @@ static int ohci_platform_resume(struct device *dev)
    > > > }
    > > >
    > > > ohci_resume(hcd, false);
    > > > +
    > > > + pm_runtime_disable(dev);
    > > > + pm_runtime_set_active(dev);
    > > > + pm_runtime_enable(dev);
    > > > return 0;
    > > > }
    > > > #endif /* CONFIG_PM_SLEEP */
    > > >
    > > >
    > > > Thanks
    > > >
    > > > --
    > > > Qais Yousef
    > >
    > >
    > >
    >

    \
     
     \ /
      Last update: 2020-04-21 13:16    [W:4.061 / U:0.080 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site