On Wed, Jan 26, 2022 at 10:58:56AM +0100, Lucas Stach wrote:
> Am Mittwoch, dem 26.01.2022 um 17:35 +0800 schrieb Shawn Guo:
> > On Thu, Dec 16, 2021 at 08:12:27AM -0800, Tim Harvey wrote:
> > > Since commit 99aa29932271 ("arm64: dts: imx8mn: Enable GPU")
> > > imx8mn-venice-gw7902 will hang during kernel init because it uses
> > > a MIMX8MN5CVTI which does not have a GPU.
> >
> > I do not quite follow on this. i.MX8MN integrates a GPU, and
> > MIMX8MN5CVTI is built on i.MX8MN, correct? If so, how comes
> > MIMX8MN5CVTI doesn't have a GPU?
> >
> It's a fused-down variant of the i.MX8MN that has the GPU disabled by
> fuses.
>
> > >
> > > Disable pgc_gpumix to work around this. We also disable the GPU devices
> > > that depend on the gpumix power domain and pgc_gpu to avoid them staying
> > > in a probe deferred state forever.
> >
> > Is this an indication that GPU should be disabled in imx8mn.dtsi and
> > enabled board by board?
> >
> There's a trade-off here: most boards will probably use the full
> variants that include the GPU, so probably less boards will need to
> disable the GPU, as done here, than boards that need to enable it when
> the base DT disables the GPU.
>
> Same story as with the i.MX6 where there are some SKUs that disable the
> VPU by fuses: we enable it in the base DT and if you happen to build a
> very low-cost board that uses the fused-down version you need to
> disable it in the board DT.
Thanks, Lucas!
Patch applied!
Shawn
