Am Dienstag, 19. Januar 2010 17:27:46 schrieb Alan Cox: > On Tue, 19 Jan 2010 16:25:36 +0100 > Johan Hovold <jhovold@xxxxxxxxx> wrote: > > Is it really a fix? If the fifo is already full the write urb should be > > in use and Oliver's patch would amount to only a minor optimisation as > > usb_serial_generic_write_start would return 0 anyway. > > IF the write returns a zero then it will sleep in n_tty waiting for a > wakeup when the FIFO level drops sufficiently. If that isn't working > check that all cases where data is cleared from the FIFO called > tty_wakeup and do so *after* the FIFO has been partly emptied and the > locking has ensured the space is visible to the write side. > usb_serial_generic_write_bulk_callback() always calls the softint in the single URB case. Therefore the test with the patch I sent. It is unlikely to be chance that the hang happens just as the FIFO is full. Regards Oliver -- 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
