On 7/26/07, Marcus Comstedt <[EMAIL PROTECTED]> wrote: > > "Peter Bortas" <[EMAIL PROTECTED]> writes: > > > On 7/21/07, Adrian McMenamin <[EMAIL PROTECTED]> wrote: > >> On 21/07/07, Peter Bortas <[EMAIL PROTECTED]> 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. > > > I don't remeber any such delay. Are you sure you're not thinking > about the G2 bus problem (where accesses need to be programatically > serialized, whether they are PIO or DMA)?
In that case my memory is worse than I thought. I'll see if I can dig up my old notes. -- Peter Bortas - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
