Re: [PATCH 2/4] clk: qcom: Add clk_rcg2_gfx3d_ops for SDM845

From: Stephen Boyd
Date: Thu Aug 02 2018 - 18:44:40 EST


Quoting Amit Nischal (2018-07-30 04:28:56)
> On 2018-07-25 12:28, Stephen Boyd wrote:
> >
> > Ok. Sounds good! Is the rate range call really needed? It can't be
> > determined in the PLL code with some table or avoided by making sure
> > GPU
> > uses OPP table with only approved frequencies?
> >
>
> Currently fabia PLL code does not have any table to check this and
> intention
> was to avoid relying on the client to call set_rate with only approved
> frequencies so we have added the set_rate_range() call in the GPUCC
> driver
> in order to set the rate range.
>

But GPU will use OPP so it doesn't seem like it really buys us anything
here. And it really doesn't matter when the clk driver implementation
doesn't use the min/max to clamp the values of the round_rate() call. Is
that being done here? I need to double check. I would be more convinced
if the implementation was looking at min/max to constrain the rate
requested.