On Sat, 18 Aug 2012, Bruno Prémont wrote:
Hi Jiri,
[CCing Alan Stern]
On Thu, 16 August 2012 Jiri Kosina [off-list ref] wrote:
quoted
On Thu, 16 Aug 2012, Bruno Prémont wrote:
quoted
quoted
I don't really understand this explanation. Once usb_kill_urb() returns,
the URB should be available for future use (and therefore all queues
completely drained).
I won't have time today to check, though my guess is that on each
echo $usb-id > bind; echo $usb-id > unbind
under /sys/bus/hid/drivers/hid-picolcd/ the USB urb queue fills a bit does
not get cleared.
Is usb_kill_urb() called when unbinding just the specific hid driver?
Yup, through hid_hw_stop() -> usbhid_stop().
quoted
If so my short timing between bind/unbind must be triggering something
else...
Otherwise I'm missing something as at first time I got no "output queue full"
messages, but as I repeated the bind/unbind sequences the prints per bind/unbind
iteration increased in number.
Anyhow, on Friday evening/week-end I will continue digging and report back with my
findings.
Huh, after changing some of the hid-picolcd data in order to have less racy
coupling between hid and framebuffer I'm now dying way too often in _mmx_memcpy
and most of the time I don't get a (complete) trace...
There was a similar problem reported recently. It turned out to be
caused by a __devinitconst annotation attached to a usb_device_id
table.
If there are any __devinit* annotations in the hid-picolcd driver, you
should see if removing them helps.
Alan Stern