Re: 2.6.25-rc7: Ugh.

[Mark Lord <lkml@rtr.ca>]

Greg KH wrote:
> On Thu, Mar 27, 2008 at 11:29:27AM -0400, Mark Lord wrote:
>> It is with great reluctance when I attempt moving my main "desktop"
>> over to a new kernel version -- because the USB subsystem seems to
>> break every single time.
> 
> That's not good, why not tell the linux-usb developers this?  (added to
> the cc:)
> 
>> So today I tried 2.6.25-rc7 on it for the first time.
>> Not good.
>>
>> It boots, but just a simple suspend/resume (RAM) was enough to kill it.
>> It comes back on resume, with an X desktop again,
>> but with no USB functionality -- no mouse.
>>
>> The keyboard still works, so I dropped to a console and tried:
>>
>>   rmmod usbhid
>>   insmod usbhid
>>
>> And the console hung at 100% CPU on the insmod.
..

Okay, correction there:  it just hangs the console, but not 100% CPU.
Other tasks still continue running.

Same thing happens when I rmmod usbhid, and then rmmod ehci_hcd.
The rmmod ehci_hcd hangs.

But since the rest of the system is still alive, including the non-USB touchpad(!),
here is the alt-sysrq-t from syslog:

rmmod         D f74c2ddc     0  4538   4492
       f6d3b200 00000086 f74c2c90 f74c2ddc c281e840 00000001 c01131be 00000000 
       00000001 c0324a00 c0324a00 00000000 00000001 7fffffff 7fffffff f653cea8 
       00000002 c02906f8 00000000 00000012 c038f6aa 00000086 c011aa05 00000000 
Call Trace:
 [__wake_up_common+46/88] __wake_up_common+0x2e/0x58
 [schedule_timeout+19/134] schedule_timeout+0x13/0x86
 [wake_up_klogd+43/45] wake_up_klogd+0x2b/0x2d
 [wait_for_common+205/308] wait_for_common+0xcd/0x134
 [default_wake_function+0/8] default_wake_function+0x0/0x8
 [__cancel_work_timer+237/312] __cancel_work_timer+0xed/0x138
 [wq_barrier_func+0/8] wq_barrier_func+0x0/0x8
 [<f889f684>] usb_remove_hcd+0x63/0xd7 [usbcore]
 [<f88a858e>] usb_hcd_pci_remove+0x15/0x68 [usbcore]
 [pci_device_remove+22/53] pci_device_remove+0x16/0x35
 [__device_release_driver+88/118] __device_release_driver+0x58/0x76
 [driver_detach+122/182] driver_detach+0x7a/0xb6
 [bus_remove_driver+96/126] bus_remove_driver+0x60/0x7e
 [pci_unregister_driver+30/95] pci_unregister_driver+0x1e/0x5f
 [sys_delete_module+388/445] sys_delete_module+0x184/0x1bd
 [remove_vma+49/54] remove_vma+0x31/0x36
 [do_page_fault+506/1232] do_page_fault+0x1fa/0x4d0
 [sysenter_past_esp+95/133] sysenter_past_esp+0x5f/0x85
 =======================

If nothing else, this should point to where USB is getting deadlocked.

??