Re: jgarzik and max-sectors: out of memory

[Jens Axboe <axboe@suse.de>]

On Saturday 27 May 2006 21:37, Jeff Garzik wrote:
> ATA_MAX_SECTORS is 200, rather than than 256 like it should be.  I seem
> to recall that this was due to libata being incomplete in some area, but
> I've tried in vain for a year to remember where the alleged
> incompleteness was, to no avail.  So, my brain is out of memory :)
>
> Further -- someone with a long ATA memory correct me -- I think that we
> can increase ATA_MAX_PRD beyond 256.  Most DMA engines should just keep
> chugging along, provided that we continue to respect the 64k IDE DMA
> boundaries.

The PRD count is much less of a problem.

> So, I propose that we rename ATA_MAX_SECTORS to ATA_LBA28_SECTORS, and
> change its value to 256, and see what happens.  People have reported
> that that worked for them, so let's subject it to a wide test.  If
> people are extremely paranoid, we could increase it to 255, and then in
> the next kernel version, bump it from 255 to 256.
>
> Then we can look at increasing ATA_MAX_PRD, if that's feasible for PATA
> hardware.

Yep lets please do that, I don't think libata ever had any problems with 256 
sectors other than perhaps a worry that it would break "something" :-)

Jens