• David Moore's avatar
    firewire: fw-ohci: Bug fixes for packet-per-buffer support · bcee893c
    David Moore authored
    This patch corrects a number of bugs in the current OHCI 1.0
    packet-per-buffer support:
    
    1. Correctly deal with payloads that cross a page boundary.  The
    previous version would not split the descriptor at such a boundary,
    potentially corrupting unrelated memory.
    
    2. Allow user-space to specify multiple packets per struct
    fw_cdev_iso_packet in the same way that dual-buffer allows.  This is
    signaled by header_length being a multiple of header_size.  This
    multiple determines the number of packets.  The payload size allocated
    per packet is determined by dividing the total payload size by the
    number of packets.
    
    3. Make sync support work properly for packet-per-buffer.
    
    I have tested this patch with libdc1394 by forcing my OHCI 1.1
    controller to use the packet-per-buffer support instead of dual-buffer.
    
    I would greatly appreciate testing by those who have a DV devices and
    other types of iso streamers to make sure I didn't cause any
    regressions.
    
    Stefan, with this patch, I'm hoping that libdc1394 will work with all
    your OHCI 1.0 controllers now.
    
    The one bit of future work that remains for packet-per-buffer support is
    the automatic compaction of short payloads that I discussed with
    Kristian.
    Signed-off-by: default avatarDavid Moore <dcm@acm.org>
    Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
    bcee893c
fw-ohci.c 58.6 KB