Re: [PATCH] aic94xx: fix SMP request DMA direction

Muli Ben-Yehuda
2007-09-30T07:26:56Z

On Sun, Sep 30, 2007 at 12:13:55AM -0700, Darrick J. Wong wrote:

> Actually, SMP commands are used during device discovery to find
> things attached to expanders, so it seems likely that "it blows up
> almost immediately after loading the module" symptoms are a result
> of this bug.
>
> That said, the bug that Jeff fixed resulted in extra permissions
> (+w) being set for the SMP request buffer, so that's probably why
> I've never seen any problems manifesting on x260/x3800 systems.
>
> (Unless the CalIOC2 has a write only mode?)

It does (you can turn on each of the R and W bits in the TCE entry
seperately) but we don't make use of it - we set it to either none, RO
or RW.

Cheers,
Muli