On 03/20/2014 11:16 PM, Sarah Sharp wrote:
On Wed, Mar 19, 2014 at 12:37:37PM +0100, Andreas Reis wrote:
I've uploaded a dmesg with the new debugging patch to bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=130041
Andreas Reis
On 18.03.2014 15:57, Alan Stern wrote:>
The debugging information didn't go far enough. Try the patch below
instead, which has some additional messages.
There are two apparently separate problems here. First, why was the
reset necessary? As far as I can tell, the only explanation seems to
be a failure of Link Power Management.
Second, why the errors in queuecommand_lck? I suspect the answer to
that lies somewhere in the SCSI subystem, not USB. The new debugging
patch should tell us for sure.
Mathias, you might want to come up with a patch to disable link PM and
see if it helps in this case.
That could be as simple as not setting XHCI_INTEL_HOST for this PCI
device ID, or could be as complex as exposing a sysfs file similar to
usb2_hardware_lpm. It could also have something to do with how we set
the U1/U2 timeouts for this particular device. Exposing a file to play
with those settings may be interesting.
I'll let you handle triaging the xHCI bug reports, but please let me
know if you get stuck.
I'm on it, I'm right now digging through the USB3 LPM code and trying to
figure out where to include useful debug messages.
Goal is to have some debugging patch by tomorrow that Andreas could try.
-Mathias
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