Messages in this thread | | | Date | Thu, 18 Apr 2002 15:26:50 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] IDE TCQ #4 |
| |
On Thu, Apr 18 2002, Martin Dalecki wrote: > Jens Axboe wrote: > >On Thu, Apr 18 2002, Martin Dalecki wrote: > > > >>Jens Axboe wrote: > >> > >>>On Thu, Apr 18 2002, Martin Dalecki wrote: > >>> > >>> > >>>>Jens Axboe wrote: > >>>> > >>>> > >>>>>On Thu, Apr 18 2002, Martin Dalecki wrote: > >>>>> > >>>>> > >>>>> > >>>>>>BTW> Jens: Do you have any idea what the "sector chaing" in ide-cd is > >>>>>>good for?! I would love to just get rid of it alltogether! > >>>>> > >>>>> > >>>>>Sector chaining? Are you talking about the cdrom_read_intr() comments? > >>>> > >>>>Sorry I did mean sector caching. > >>> > >>> > >>>That's for padding/caching sub-frame sized reads. > >> > >>I tought the BIO layer did this alredy... Well it's a pain > > > > > >Nope, it does not. > > > > > >>in the a** to deal with it. IDE-FLOPPY is passing packet commands > > > > > >It sure is... sr doesn't do it and lots of others don't as well, so I > >suppose we could rip it out. We already require reblocking with loop in > >those cases anyway. > > > > > >>through the request buffer but IDE-CD is passing them through > >>request special field... argh! > > > > > >So kill ->special usage in ide-cd and use ->buffer? > > That's the idea, but the caching code mentioned above > is abusing it already in a way I can't grasp wholly immediately.
It's most definitely _not_ abusing it, in fact it's a pretty regular usage of ->buffer. ide-cd never does highmem I/O, so ->buffer always points to the transfer address for a block request. cdrom_read_from_buffer() is simply copying data from the internal 2kb cache to rq->buffer, eod.
-- Jens Axboe
- 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/
| |