lkml.org 
[lkml]   [2009]   [Oct]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: uvcvideo causes ehci_hcd to halt
    Alan Stern wrote:

    (Add uvcvideo maintainer to CC)
    > [ 420.737748] usb 1-5: link qh1024-0001/f6ffe280 start 1 [1/0 us]
    >
    >
    > The periodic schedule was enabled here.
    >
    >
    >> [ 420.737891] usb 1-5: unlink qh1024-0001/f6ffe280 start 1 [1/0 us]
    >>
    >
    > And it was disabled here. Do you have any idea why the uvcvideo driver
    > submits an interrupt URB and then cancels it 150 us later? The same
    > thing shows up in the usbmon traces.
    >
    >
    >> [ 420.741605] usb 1-5:1.0: uevent
    >> [ 420.741957] usb 1-5: uevent
    >> [ 420.745592] usb 1-5:1.0: uevent
    >> [ 420.807880] ehci_hcd 0000:00:1d.7: reused qh f6ffe280 schedule
    >> [ 420.807894] usb 1-5: link qh1024-0001/f6ffe280 start 1 [1/0 us]
    >>
    >
    > Now ehci-hcd tried to re-enable the periodic schedule. Note that
    > this is 70 ms after it was supposed to be disabled.
    >
    >
    >> [ 420.808780] ehci_hcd 0000:00:1d.7: force halt; handhake f7c6a024
    >> 00004000 00000000 -> -110
    >>
    >
    > This error message means that the disable request from 70 ms earlier
    > hasn't taken effect. It looks like a nasty hardware bug -- the
    > controller is supposed to disable the schedule no more than 2 ms after
    > being told to do so.
    >
    > Has this device ever worked with any earlier kernels?
    >

    I only tried 2.6.30.9 and 2.6.31.4, both of them is affected by the same
    problem but sometimes it works without a problem so I think that this
    can be interpreted as *at-least-working* on those kernels from time to time.

    > A little more debugging information could confirm this. After the
    > error occurs, go into /sys/kernel/debug/usb/ehci/0000:00:1d.7 and post
    > a copy of the "registers" file. If there's anything of interest in the
    > other files, post them too.
    >

    OK I'll look at them tomorrow, Thanks.



    \
     
     \ /
      Last update: 2009-10-21 17:41    [W:3.665 / U:0.000 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site