Hi all, There seems to have been a bug introduced in the recent kernels relating to usbdevfs syscalls. My application is constantly submitting and reaping URBs using the USBDEVFS ioctls. In recent kernels, if I disconnect the device while the application is in the USBDEVFS_REAPURB ioctl call, ioctl never returns, causing the application to freeze. At this point, dmesg shows the kernel has detected the disconnect. If I then background the application and return it to the foreground, the ioctl returns with errno = EINTR and subsequent calls to ioctl properly return with errno = ENODEV. Since the libusb library uses the USBDEVFS_REAPURB ioctl call inside the usb_bulk_read and usb_bulk_write functions, this particular issue should be of general interest as well. I am able to reproduce this behavior on kernels 2.6.23.1, 2.6.26.8, and 2.6.28.5. If I disconnect the device when running kernel 2.6.20, the USBDEVFS_REAPURB ioctl never gets stuck in the manner described above. Unfortunately, due to a lack of time, I am unable to determine the first kernel version that introduces this bug. I was wondering if any one is aware of the bug, or has any idea why this is happening in the newer kernels? Thanks, Leonid -- 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
