lkml.org 
[lkml]   [2013]   [Jan]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: USB device cannot be reconnected and khubd "blocked for more than 120 seconds"
On Sat, 12 Jan 2013, Alex Riesen wrote:

> On Sat, Jan 12, 2013 at 8:39 PM, Alex Riesen <raa.lkml@gmail.com> wrote:
> > On Sat, Jan 12, 2013 at 6:37 PM, Alan Stern <stern@rowland.harvard.edu> wrote:
> >> On Sat, 12 Jan 2013, Alex Riesen wrote:
> >>> One more detail: I usually use the "noop" elevator. That time it was
> >>> the "deadline". And I just reproduced it easily with "deadline".
> >>
> >> I doubt the elevator has anything to do with this.
> >
> > But it looks like it does: just using the deadline elevator is a sure way
> > to reproduce the bug. The system always recovers (sometimes after a while)
> > with "noop".
>
> And no, it does not. Not by itself, but the fact that deadline elevator was
> compiled as module certainly helped!
>
> This explains the hanging modprobe in the dmesg output (the part after device
> connect). I still wonder, why didn't it froze at boot, mounting SATA devices
> (the root, /var, and /home are on an SSD connected by SATA)? And why hanging
> khubd at reboot?
>
> Anyway, building the elevator in the kernel avoids the problem. Sorry for
> not spotting this earlier.
>
> Now, who would be interested to handle this kind of misconfiguration ...

So the whole thing was a false alarm?

Maybe you should report to the block-layer maintainers that it's
possible to mess up the system by building an elevator as a module.
That sounds like the sort of thing they'd be interested to hear.

Alan Stern



\
 
 \ /
  Last update: 2013-01-13 00:21    [W:0.092 / U:0.384 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site