On Mon, 27 Feb 2012, Adrien Decostre wrote: > Dear all, > > I am currently doing some tests to communicate with an USB HID device > by means of the HIDAPI and libusb libraries on a Linux x64 > distribution. > One of these tests consists basically of successive enumeration cycles: > -��opening the hid device > -��exchanging some data between the host and the device > -��at some point, closing the communication with the hid device > -��wait a few second and reiterate the above steps > > This test runs correctly a few times and then suddenly crashes. > Apparently, this crash happens in a random way. > > The strange point is that after this crash, the file system in RAM is > "corrupted": some folders like �etc� have disappeared and I have to > reboot the kernel. I have no idea what could be causing that corruption, unless the filesystems in question reside on a USB drive. > The crash has been seen on 2 different machines: > - on x64 Ubuntu 2.6.35 based kernel (Ubuntu 10.10) > - on x64 Angstr�.6.39 based kernel (the log given below have been > obtained on this machine). On this last machine, the crash happens > only on the 2nd usb bus. When the test usb device is connected to the > 1st bus usb, I have not seen any problem up to now. > > When looking to the dmesg output, the crash seems to be caused by the > kworker process. The crash log starts with a crash of the ehci driver > (see below for a complete dmesg log): > ehci_hcd 0000:00:13.2: force halt; handshake ffffc90000070024 00004000 > 00000000 -> -110 > ehci_hcd 0000:00:13.2: HC died; cleaning up > usb 2-4: usbfs: usb_submit_urb returned -110 > usb 2-3: USB disconnect, device number 2 > > In the past days, I have been looking for a possible bug in my test > application or in the HIDAPI / libusb libraries (cf. > http://libusb.6.n5.nabble.com/Application-using-HIDAPI-and-libusb-causes-file-system-corruption-td5508578.html) > but I am now wondering if this could be related to a known issue in > the kernel. It's a known bug in the EHCI hardware in quite a few different platforms. Here's an experimental patch to work around it: http://marc.info/?l=linux-usb&m=132440828606642&w=2 You may have to do some hand editing to get that patch to apply, because you're using some old kernels. > Has someone already seen a similar issue with any application? > Could a bug in an userspace application cause this kernel crash? Most unlikely. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
