• Alan Stern's avatar
    USB: EHCI: fix bug in scheduling periodic split transfers · 3e619d04
    Alan Stern authored
    This patch (as1654) fixes a very old bug in ehci-hcd, connected with
    scheduling of periodic split transfers.  The calculations for
    full/low-speed bus usage are all carried out after the correction for
    bit-stuffing has been applied, but the values in the max_tt_usecs
    array assume it hasn't been.  The array should allow for allocation of
    up to 90% of the bus capacity, which is 900 us, not 780 us.
    
    The symptom caused by this bug is that any isochronous transfer to a
    full-speed device with a maxpacket size larger than about 980 bytes is
    always rejected with a -ENOSPC error.
    Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
    Cc: stable <stable@vger.kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    3e619d04
ehci-sched.c 60.6 KB