lkml.org 
[lkml]   [2010]   [Sep]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [34-stable regression] USB delay init quirk causes device events loss
    On Mon, Sep 13, 2010 at 11:37:49AM -0400, Alan Stern wrote:
    > On Mon, 13 Sep 2010, Jiri Slaby wrote:
    >
    > > On 09/13/2010 04:48 PM, Alan Stern wrote:
    > > > On Mon, 13 Sep 2010, Jiri Slaby wrote:
    > > >> In other words, what I could do is to add some printks into
    > > >> hub_port_connect_change if that's called at all. If you need some
    > > >> thorough debugging printks, please send me a patch to test instead.
    > > >
    > > > Hmm. I'd prefer to explain how it's all supposed to work and let you
    > > > figure out where best to look. Or try to debug it myself. Does this
    > > > happen with other sorts of USB devices as well, or just wacom?
    > >
    > > With some sort of devices (I cannot reproduce myself). It's unrelated to
    > > wacom -- people with wacom were unable to even start X with this kernel.
    > > If you look at the bugreport, there are several examples:
    > > ID 046d:c517 Logitech, Inc. LX710 Cordless Desktop Laser defunct
    > > Microsoft USB keyboard defunct x Logitech mice OK
    > > 046a:0021 Cherry GmbH keyboard defunct
    > > logitech wireless laptop mouse defunct
    > > A$Tech wireless laptop mouse defunct
    > > TypeMatrix USB 2030 (ID : 1e54:2030) defunct
    >
    > Okay, I see the problem. By moving usb_detect_quirks earlier, we end
    > up calling usb_disable_autosuspend too soon -- before the
    > pm_runtime_enable call in usb_new_device. In 2.6.35 this doesn't
    > matter because the implementation of usb_autosuspend_device has
    > changed.
    >
    > So yes, in the end it looks like the best course is to revert this
    > patch from 2.6.34.stable. This is unfortunate but I don't see any way
    > around it without making changes that aren't present in the current
    > kernel. For example, the pm_runtime_set_active and pm_runtime_enable
    > calls could also be moved from usb_new_device into
    > hub_port_connect_change.

    Ok, I'll go revert that from the .34-stable tree and do a new release,
    as it's not nice to have a broken tree out there.

    thanks,

    greg k-h


    \
     
     \ /
      Last update: 2010-09-13 18:01    [W:0.020 / U:2.008 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site