Re: [PATCH v3 1/8] drm/i915/skl: Add support to load SKL CSR firmware

Imre Deak
2015-04-13T16:53:01Z

On Mon, 2015-04-13 at 17:34 +0100, Damien Lespiau wrote:
> On Mon, Apr 13, 2015 at 03:54:02PM +0530, Animesh Manna wrote:
> > diff --git a/drivers/gpu/drm/i915/intel_csr.h b/drivers/gpu/drm/i915/intel_csr.h
> > new file mode 100644
> > index 0000000..c2a5a53
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/intel_csr.h
> > +
>
> [...]
>
> > +#define I915_CSR_SKL "i915/dmc_gen9.bin"
>
> I'm guessing the BXT DMC firwmare will be different from SKL's? Remember
> that one of the requirements is to be able to have the same OS image
> boot on both SKL and BXT. That means the firmware names have to be
> different for SKL and BXT. We probably should have skl in the name here.
>
> Also, we need to be able to be able to support "Interface" versions. Ie.
> if the firmware interface changes in such a way a different loading code
> is needed, we need to be able to have both firmware on the disk so both
> an old kernel and a new kernel can work with the same user space.
>
> Right now, the naming scheme of the firmware does have a version on it,
> hopefully that's this "Interface" version.
>
> Thoughts?

Yes, the above file name looks incorrect. "dmc_gen9.bin" was the name
for the firmware image with the old layout. This patchset adds support
for the new firmware layout starting from ver 1, while the old layout
doesn't need to be supported. In an earlier version of this patch the
filename was changed to "i915/skl_dmc_ver1.bin" not sure why that change
got dropped. I think we could just use this latter name.

--Imre