lkml.org 
[lkml]   [2007]   [Jul]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] Fix DMA on Dreamcast
    On 7/21/07, Adrian McMenamin <adrianmcmenamin@gmail.com> wrote:
    > On 21/07/07, Peter Bortas <bortas@gmail.com> wrote:
    >
    > >
    > > Sidenote: Does Linux handle the Dreamcast DMA errata?
    > >
    >
    > You need to explain what you mean (at least to me!).
    >
    > If you mean will it degrade gracefully - not without this patch if set
    > to the (correct) defconfig. With iffy settings it will.

    If I remember correctly (and that's a big if since I last looked at it
    in 2001) some revisions of the Dreamcast hardware would sporadically
    lock up if you scheduled a new DMA request to quickly after a previous
    one, even if you checked the ready bit. It's worked around by a delay
    of X microseconds as recommended by Sega engineers. I don't remember
    the value of X, nor where exactly in the flow this workaround should
    be applied.

    Adding Marcus in case he has a better memory than me.

    --
    Peter Bortas
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-07-21 16:15    [W:0.035 / U:1.716 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site