Kernel Bug Tracker – Bug 5164
pl2303 when unplugged while device is open leaks semaphore
Last modified: 2006-02-14 17:40:03 UTC
Most recent kernel where this bug did not occur:
Distribution: suse 9.3
Hardware Environment:athlon64 / x86-64 VIA chipset OHCI
Steps to reproduce:
I had a serialconnection open to a pl2303 ttyUSB0 device. Then the USB cable
was unplugged. The serial connection was closed as expected, but afterwards
lsusb hangs. Plugging in the cable again also doesn't make the device
Backtrace of lsusb:
lsusb D ffff810065046b30 0 22153 26510 22152 (NOTLB)
ffff8100522fdde8 0000000000000082 0000000000000d19 ffff810065046b30
ffffffff803f3780 ffff81000d0fbae8 ffff8100721152a8 6db6db6db6db6db7
My guess is that the semaphore isn't "leaked", but instead the disconnect
routine either crashes or hangs while holding the semaphore. What does your
stack dump show for the khubd thread?
Has there been any progress chasing this bug? Does it still occur in the latest
Please test 2.6.14-rc3 or later. If it still happens, please reopen this bug.
Note, I can't duplicate this at all on 2.6.14-rc3. This is on i386 though...
Am marking closed. If you still have this problem on the 2.6.16 kernel, please
reopen it and let us know.