Re: [PATCH 2/3] soc: qcom: stats: Add fixed sleep stats offset for older RPM firmwares

[Stephan Gerhold <stephan@gerhold.net>]

On Thu, Nov 18, 2021 at 02:58:50PM -0600, Bjorn Andersson wrote:
> On Thu 18 Nov 04:45 CST 2021, Stephan Gerhold wrote:
> 
> > On Wed, Nov 17, 2021 at 07:00:58PM -0600, Bjorn Andersson wrote:
> > > On Mon 18 Oct 06:08 CDT 2021, Stephan Gerhold wrote:
> > > 
> > > > Not all RPM firmware versions have the dynamic sleep stats offset
> > > > available. Older versions use a fixed offset of 0xdba0.
> > > > 
> > > > Add support for this using a new qcom,rpm-legacy-stats compatible
> > > > that can be used for older SoCs like MSM8916.
> > > > 
> > > > Suggested-by: Maulik Shah <mkshah@codeaurora.org>
> > > > Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> > > > ---
> > > >  drivers/soc/qcom/qcom_stats.c | 10 ++++++++++
> > > >  1 file changed, 10 insertions(+)
> > > > 
> > > > diff --git a/drivers/soc/qcom/qcom_stats.c b/drivers/soc/qcom/qcom_stats.c
> > > > index 817505bd99b5..67728de718fd 100644
> > > > --- a/drivers/soc/qcom/qcom_stats.c
> > > > +++ b/drivers/soc/qcom/qcom_stats.c
> > > > @@ -237,6 +237,15 @@ static const struct stats_config rpm_data = {
> > > >  	.subsystem_stats_in_smem = false,
> > > >  };
> > > >  
> > > > +/* Older RPM firmwares have the stats at a fixed offset instead */
> > > > +static const struct stats_config rpm_legacy_data = {
> > > > +	.stats_offset = 0xdba0,
> > > > +	.num_records = 2,
> > > > +	.appended_stats_avail = true,
> > > > +	.dynamic_offset = false,
> > > > +	.subsystem_stats_in_smem = false,
> > > > +};
> > > 
> > > Is this the only variation that existed back in the "legacy" days? Will
> > > we end up with multiple "legacy" variants?
> > > 
> > 
> > I think most old platforms that are still somewhat maintained use 0xdba0
> > (e.g. MSM8916, MSM8974, APQ8084, MSM8226).
> > I found a different offset for APQ8064, MSM8960, but they also seem to
> > use a different stats format ("v1" instead of "v2") which is not
> > currently supported by the qcom_stats driver here.
> > 
> 
> Okay, so there's an even more legacy format as well...
> 

We could use qcom,rpm-even-more-legacy-stats for those. ;D (just kidding)

> > I guess I could add SoC-specific compatibles if you prefer (e.g.
> > "qcom,rpm-stats-msm8916"), or do you have any other suggestion?
> > 
> 
> Yes, as we have examples of another "legacy format" I would prefer that
> we sprinkle some platform names in there; and as newer platforms all
> seems to use the same format this effort should be bound to whatever old
> platforms we end up supporting.
> 
> Nit. I would prefer the qcom,msm8916-rpm-stats format though.
> 

Both sound good to me, I will send a v2 with the
"qcom,msm8916-rpm-stats" compatible instead.

Thanks,
Stephan