On Mon, Sep 08, 2008 at 08:38:20PM +0100, Nick Leverton wrote: > Package: linux-image-2.6.26-1-686 > Version: 2.6.26-4 > Severity: serious > Justification: lenny/rc-policy > > I have a USB "Express" twin port serial adaptor, which identifies itself > as USB ID 9710:7840 MosChip Semiconductor. This uses the mos7840 Moschip > 7840/7820 USB Serial Driver. > > On linux-image-2.6.26-1-686 version 2.6.26-3 this adaptor worked fine > and neither of the following problems occurred. > > On linux-image-2.6.26-1-686 version 2.6.26-4 there are serious problems. > > First, the usb-serial ports do not work correctly. Whatever character > I send to the tty, it emits the letter 'O' from the serial port. > See the two strace attachments, which are from kernels 2.6.26-3 and > 2.6.26-4 respectively. They were generated using minicom talking to a > serial device which just echoes the input and sends the prompt "Ready" > when it receives a carriage return. > > Unfortunately I didn't type the same characters in each test, but > if you diff the straces you can see that the tiocmget behaviour is > substantially changed in what it returns, in addition to the incorrect > character being sent. > > Secondly, on unplugging the adaptor, a kernel OOPS is caused due to a > null pointer dereference. See dmesg extract also attached. > > Following this OOPS, lsusb just hangs and is not interruptible with > control-C, and on attempting to shut down the machine the shutdown process > hangs when closing down Bluetooth (the built-in Bluetooth adaptor also > presents a USB interface). Magic sysrq key still works fortunately ! > > A different usb-serial device using the ftdi-sio driver still works > without error. > > I see the following in the package changelog and wonder if this change > is related to the destabilisation ? > > linux-2.6 (2.6.26-4) unstable; urgency=low > * Add stable release 2.6.26.3: > - usb-serial: don't release unregistered minors
The commit in question is http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.26.y.git;a=commit;h=bb457a9869e945299445f13bf618975d1562ab83 Please try to a kernel build with that fix reverted. If it fixes the problem for you, please pass your debug data to Greg Kroah-Hartman <[EMAIL PROTECTED]>, who's both one of the maintainers of the 2.6.26.x stable releases and the Linux USB maintainer. Cheers, Moritz -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
