Re: [PATCH v2 05/11] clk: qcom: gcc-msm8998: Mark gpu_cfg_ahb_clk as critical

[AngeloGioacchino Del Regno]

Il 08/02/21 19:18, Stephen Boyd ha scritto:
> Quoting AngeloGioacchino Del Regno (2021-01-14 14:10:53)
> > The GPU IOMMU depends on this clock and the hypervisor will crash
> > the SoC if this clock gets disabled because the secure contexts
> > that have been set on this IOMMU by the bootloader will become
> > unaccessible (or they get reset).
> > Mark this clock as critical to avoid this issue when the Adreno
> > GPU is enabled.
> >
> > Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
> > ---
> >   drivers/clk/qcom/gcc-msm8998.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/clk/qcom/gcc-msm8998.c b/drivers/clk/qcom/gcc-msm8998.c
> > index c8d4c0348952..afea60a3ef43 100644
> > --- a/drivers/clk/qcom/gcc-msm8998.c
> > +++ b/drivers/clk/qcom/gcc-msm8998.c
> > @@ -2081,6 +2081,12 @@ static struct clk_branch gcc_gpu_cfg_ahb_clk = {
> >                  .hw.init = &(struct clk_init_data){
> >                          .name = "gcc_gpu_cfg_ahb_clk",
> >                          .ops = &clk_branch2_ops,
> > +                       /*
> > +                        * The GPU IOMMU depends on this clock and hypervisor
> > +                        * will crash the SoC if this clock goes down, due to
> > +                        * secure contexts protection.
> > +                        */
> > +                       .flags = CLK_IS_CRITICAL,
> >                  },
> >          },
>
> Please send a followup patch that hits the branch on at probe time and
> removes this clk from the kernel. That will save some memory and
> overhead of worrying about this clk.

Will do!