Messages in this thread | | | Date | Thu, 3 Aug 2006 08:29:03 +0200 | From | Willy Tarreau <> | Subject | Re: Bug with USB proc_bulk in 2.4 kernel |
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On Wed, Aug 02, 2006 at 11:00:58PM -0700, Pete Zaitcev wrote: > Replace the semaphore exclusive_access with an open-coded lock for > the special use. The lock can be taken for: read, write, and both. > This way, two bulk URBs can be submitted simultaneously with ioctl > USBDEVFS_BULK: one read and one write. Such access was possible > before 2.4.28. > > Signed-off-By: Pete Zaitcev <zaitcev@redhat.com> > > --- > > The semaphore was introduced in 2.4.28 for the purpose of exclusion > between access from device.c (cat /proc/bus/usb/devices), devio.c > through libusb, and in-kernel driver. Currently, only usb-storage > observes the locking protocol. The most popular device which locks > in case of simultaneous access is TEAC CD-210PU.
Perfect. Patch queued, thanks Pete.
Willy
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