Re: [PATCH v6 2/4] media: venus: pm_helpers: use opp-table for the frequency

[Renjiang Han]

On 12/23/2024 10:17 PM, Konrad Dybcio wrote:
> On 19.12.2024 6:41 AM, Renjiang Han wrote:
> > The frequency value in the opp-table in the device tree and the freq_tbl
> > in the driver are the same.
> >
> > Therefore, update pm_helpers.c to use the opp-table for frequency values
> > for the v4 core.
> > If getting data from the opp table fails, fall back to using the frequency
> > table.
> >
> > Signed-off-by: Renjiang Han<quic_renjiang@xxxxxxxxxxx>
> > ---
> >   drivers/media/platform/qcom/venus/pm_helpers.c | 53 +++++++++++++++++++-------
> >   1 file changed, 39 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/media/platform/qcom/venus/pm_helpers.c b/drivers/media/platform/qcom/venus/pm_helpers.c
> > index 33a5a659c0ada0ca97eebb5522c5f349f95c49c7..b61c0ad152878870b7223efa274e137d3636433b 100644
> > --- a/drivers/media/platform/qcom/venus/pm_helpers.c
> > +++ b/drivers/media/platform/qcom/venus/pm_helpers.c
> > @@ -43,14 +43,20 @@ static int core_clks_enable(struct venus_core *core)
> >   	const struct venus_resources *res = core->res;
> >   	const struct freq_tbl *freq_tbl = core->res->freq_tbl;
> >   	unsigned int freq_tbl_size = core->res->freq_tbl_size;
> > +	struct device *dev = core->dev;
> > +	struct dev_pm_opp *opp;
> >   	unsigned long freq;
> >   	unsigned int i;
> >   	int ret;
> >   
> > -	if (!freq_tbl)
> > -		return -EINVAL;
> > -
> > -	freq = freq_tbl[freq_tbl_size - 1].freq;
> > +	opp = dev_pm_opp_find_freq_ceil(dev, &freq);
> > +	if (IS_ERR(opp)) {
> > +		if (!freq_tbl)
> > +			return -EINVAL;
> > +		freq = freq_tbl[freq_tbl_size - 1].freq;
> > +	} else {
> > +		dev_pm_opp_put(opp);
> > +	}
> I'm not super convinced how this could have ever worked without
> scaling voltage levels, by the way. Perhaps this will squash some
> random bugs :|
>
> Konrad
 Thanks for your comment.
 The default value of freq is 0, and then dev_pm_opp_find_freq_ceil is
 used to match freq to the maximum value in opp-table that is close to
 0. The frequency values ​​in opp-table and freq_tbl are the same, and
 dev_pm_opp_find_freq_ceil is used to assign the minimum value in
 opp-table to freq. So the logic is the same as before. I'm not sure if
 I've answered your concern.

--
Best Regards,
Renjiang