[PATCH] ata: sata_mv: fix sg_tbl_pool alignment

[Jason Cooper]

On Wed, Jan 16, 2013 at 09:55:55AM +0100, Soeren Moch wrote:
> On 16.01.2013 04:24, Soeren Moch wrote:
> >On 16.01.2013 03:40, Jason Cooper wrote:
> >>On Wed, Jan 16, 2013 at 01:17:59AM +0100, Soeren Moch wrote:
> >>>On 15.01.2013 22:56, Jason Cooper wrote:
> >>>>On Tue, Jan 15, 2013 at 03:16:17PM -0500, Jason Cooper wrote:

> OK, I could trigger the error
>   ERROR: 1024 KiB atomic DMA coherent pool is too small!
>   Please increase it with coherent_pool= kernel parameter!
> only with em28xx sticks and sata, dib0700 sticks removed.

Did you test the reverse scenario?  ie dib0700 with sata_mv and no
em28xx.

What kind of throughput are you pushing to the sata disk?

> >>What would be most helpful is if you could do a git bisect between
> >>v3.5.x (working) and the oldest version where you know it started
> >>failing (v3.7.1 or earlier if you know it).
> >>
> >I did not bisect it, but Marek mentioned earlier that commit
> >e9da6e9905e639b0f842a244bc770b48ad0523e9 in Linux v3.6-rc1 introduced
> >new code for dma allocations. This is probably the root cause for the
> >new (mis-)behavior (due to my tests 3.6.0 is not working anymore).
> 
> I don't want to say that Mareks patch is wrong, probably it triggers a
> bug somewhere else! (in em28xx?)

Of the four drivers you listed, none are using dma.  sata_mv is the only
one.

If one is to believe the comments in sata_mv.c:~151, then the alignment
is wrong for the sg_tbl_pool.

Could you please try the following patch?

thx,

Jason.

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