RE: [PATCHv3 00/11] staging tidspbridge: iommu migration

["Guzman Lugo, Fernando" <fernando.lugo@ti.com>]

 

> -----Original Message-----
> From: Felipe Contreras [mailto:felipe.contreras@gmail.com] 
> Sent: Tuesday, October 12, 2010 6:21 AM
> To: Guzman Lugo, Fernando
> Cc: gregkh@suse.de; felipe.contreras@nokia.com; 
> ameya.palande@nokia.com; Menon, Nishanth; 
> Hiroshi.DOYU@nokia.com; ohad@wizery.com; 
> linux-kernel@vger.kernel.org; andy.shevchenko@gmail.com; 
> linux-omap@vger.kernel.org
> Subject: Re: [PATCHv3 00/11] staging tidspbridge: iommu migration
> 
> On Mon, Oct 11, 2010 at 6:03 PM, Guzman Lugo, Fernando 
> <fernando.lugo@ti.com> wrote:
> >> On Tue, Oct 5, 2010 at 11:35 PM, Fernando Guzman Lugo 
> >> <x0095840@ti.com> wrote:
> >> > This set of patches remove the dspbridge custom mmu
> >> implementation and
> >> > use iommu module instead.
> >>
> >> I have tried this, it works for simple tests, but not real 
> use-cases.
> >> I applied all your iommu patches. How did you test this?
> >
> > Have you applied:
> >
> > - "scatterlist: define SG chain for arm architecture"
> > - "iovmm: replace __iounmap with omap_iounmap"
> > - "iovmm: add superpages support to fixed da address"
> > - "iovmm: IVA2 MMU range is from 0x11000000 to 0xFFFFFFFF"
> > - "iovmm: no gap checking for fixed address"
> 
> Yes.
> 
> > Also make sure your baseline have this patch:
> >
> > - "omap:iommu-load cam register before flushing the entry"
> 
> Huh? That's not even in v2.6.36-rc7, in which baseline is 
> this supposed to be in? Anyway, I'll try adding that.

That's is in latest Hiroshi's tree and it is really needed, Otherwise
You will have wrong traslations which can cause unexpected behavior.


> 
> > What kind of error are you getting?
> 
> Node allocation failing IIRC.

Is it falling to map the Heap??
I mean you see this trace?

	if (status)
		pr_err("%s: Failed to map memory for Heap: 0x%x\n",
		       __func__, status);

Otherwise, I don't see how that fail is related with iommu changes.

> 
> > I don't have a complete framework to test MM testcases at 
> this moment
> 
> See:
> http://felipec.wordpress.com/2010/10/08/my-arm-development-notes/
> 
> I even prepared a tarball so you just need to extract it on 
> your device. It's not difficult to test this with GStreamer, 
> and I don't see how you can be confident that they indeed 
> work without testing some real use-cases. Anyway, I'll try 
> that missing patch.

Most of time real use-cases are not so stressing like testcases
We can make to test under real stress in order to find out corner cases.
However when I test it was pretty stable and just few erros because staging
Does not have latest mailbox patches. Also I test in a .35 version of staging.
So now I am using a branch with all new patches and I will recheck and test
Again any possible issue. Also I will look at your gstreamer fail too.


Regards,
Fernando.

> 
> Cheers.
> 
> --
> Felipe Contreras
>