Re: DAC960 Bitrot

[Daniel Phillips <phillips@arcor.de>]

On Wednesday 24 July 2002 16:39, Jens Axboe wrote:
> The only changes I did to this driver where trivial conversions in the
> 2.5.1-pre days, in fact even before multi-page bio's existed. This,
> btw, is also something you should keep an eye out for -- multi-page bio
> support is currently broken.

I spotted that.  I changed bio_size (which is gone) to bio_sectors(bio) << 9, 
is this correct?

> I would suggest also moving DAC960 to the
> pci dma api (this is a must) and then move it to use the generic block
> helpers for mapping requests. That way there isn't a lot of nasty
> duplication there as well, plus it will automatically get the multi-page
> issues right.

My first concern is to get something working any way I can so that I can 
start doing regression testing.  True/false: the bad old way of doing dma 
will still work, it's just deprecated?  If true, then I should (trivially) 
switch back to the old way of doing things, get the rest working, then 
convert to the dma api.  Maybe *you* could make all the changes at the same 
time and expect to end up with something that works, but I can't.

The alternative is to go back many kernel versions and find the first one  
that broke something, but I don't want to do that because too much else was 
broken at the time.

> Hmm, is DAC960 using a full major per controller?!

As you saw, it implements the top level block interface instead of being a 
scsi device as it should be.  So for disk subsystems we have: 1) IDE 2) SCSI 
3) DAC960.  Eep.  At some point it's all going to be SCSI, right?

-- 
Daniel