Re: [BUG] IT8212 libata driver *still* hard-freezes system on boot on 2.6.22 final.

Alan Cox
2007-07-09T12:10:36Z

> > It would be useful to know if a kernel built with no DMA support for the
> > IT8212 behaved as that might give us a clue about what is choking. If you
> > look in drivers/ata/pata_it821x.c:it821x_init_one you'll see a pair of
> > lines that say
> >
> > mwdma = 0x1f,
> > udma_mask = 0x7f
> >
> >
> > remove, rebuild and report..
>
> Alright.
>
> Attachment [0] is a successful boot with those lines removed. (This a
> good thing or a bad thing? :)

Thats an interesting question in itself. It does seem to indicate the
problem is DMA tuning or DMA related and not IRQ routing - which is good
as of itself.

> Attachment [1] is a successful boot with the old ata subsystem using the
> IT8212.

For the next trick set mwdma_mask = 0x07 but leave UDMA off and see what
happens. Then try with udma_mask = 0x02 which should force the 50MHz
clock on not the 66MHz clock just in case its clock related.

How much RAM do you have ?

Alan