Messages in this thread | | | Date | Wed, 12 Mar 2008 17:44:56 -0400 (EDT) | From | Alan Stern <> | Subject | Re: broken access to a USB HID device after suspend |
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On Wed, 12 Mar 2008, Jiri Kosina wrote:
> On Wed, 12 Mar 2008, Tino Keitel wrote: > > > I use a tool called hidmon to control the parameters of my LCD in shell > > scripts. I just had the case where this tool didn't work after suspend > > to RAM. I just got this error message: > > > > hid_force_open failed with return code 13 > > > > The kernel log contains lines like this: > > > > usb 1-1.3: usbfs: USBDEVFS_CONTROL failed cmd hidmon rqt 129 rq 6 len 9 ret -110 > > > > Unplugging and replugging the USB cable of the LCD didn't work. > > However, after a further suspend/resume cycle it works. > > > > This is Linux 2.6.25-rc5. The behaviour is not repoducible, though. > > However, I just mention it for the case that this might ring a bell > > somewhere. > > This in fact looks like a problem with usbdevfs and/or libusb library, not > the in-kernel HID drvier. > > Did this work before? In 2.6.24? 2.6.23? Alan (added to CC, as well as USB > devel mailinglist) has been doing some changes to usbdevfs to make it > suspend-aware, if I recall correctly.
No, usbfs hasn't undergone any significant changes recently.
Tino, it would help to see a kernel log showing what happened during the suspend, resume, and failure of hidmon. It would help even more if you test under a kernel with CONFIG_USB_DEBUG enabled.
Even if you can't reproduce the problem, do you have the complete kernel log from before?
Is it possible that this is really a problem with the LCD device, not with the kernel? I ask because if the device was working properly then unplugging and replugging the USB cable should do a complete reset.
Alan Stern
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