• Alan Stern's avatar
    USB: revert periodic scheduling bugfix · fdc03438
    Alan Stern authored
    This patch reverts commit 3e619d04
    (USB: EHCI: fix bug in scheduling periodic split transfers).  The
    commit was valid -- it fixed a real bug -- but the periodic scheduler
    in ehci-hcd is in such bad shape (especially the part that handles
    split transactions) that fixing one bug is very likely to cause
    another to surface.  That's what happened in this case; the result was
    choppy and noisy playback on certain 24-bit audio devices.
    
    The only real fix will be to rewrite this entire section of code.  My
    next project...
    
    This fixes https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1136110.
    
    Thanks to Tim Richardson for extra testing and feedback, and to Joseph
    Salisbury and Tyson Tan for tracking down the original source of the
    problem.
    Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
    CC: Joseph Salisbury <joseph.salisbury@canonical.com>
    CC: Tim Richardson <tim@tim-richardson.net>
    Cc: stable <stable@vger.kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    fdc03438
ehci-sched.c 60.5 KB