Re: [PATCH v2 15/48] opp: Support set_opp() customization without requiring to use regulators

From: Viresh Kumar
Date: Wed Dec 23 2020 - 01:01:47 EST


On 17-12-20, 21:06, Dmitry Osipenko wrote:
> Support set_opp() customization without requiring to use regulators. This
> is needed by drivers which want to use dev_pm_opp_set_rate() for changing
> rates of a multiple clocks and don't need to touch regulator.
>
> One example is NVIDIA Tegra30/114 SoCs which have two sibling 3D hardware
> units which should be use to the same clock rate, meanwhile voltage
> scaling is done using a power domain. In this case OPP table doesn't have
> a regulator, causing a NULL dereference in _set_opp_custom().
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/opp/core.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index 3d02fe33630b..625dae7a5ecb 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -828,17 +828,25 @@ static int _set_opp_custom(const struct opp_table *opp_table,
> struct dev_pm_opp_supply *old_supply,
> struct dev_pm_opp_supply *new_supply)
> {
> - struct dev_pm_set_opp_data *data;
> + struct dev_pm_set_opp_data *data, tmp_data;
> + unsigned int regulator_count;
> int size;
>
> - data = opp_table->set_opp_data;
> + if (opp_table->set_opp_data) {
> + data = opp_table->set_opp_data;
> + regulator_count = opp_table->regulator_count;
> + } else {
> + data = &tmp_data;
> + regulator_count = 0;
> + }
> +

We should use the same structure, you can add some checks but not replace the
structure altogether.

> data->regulators = opp_table->regulators;
> - data->regulator_count = opp_table->regulator_count;
> + data->regulator_count = regulator_count;
> data->clk = opp_table->clk;
> data->dev = dev;
>
> data->old_opp.rate = old_freq;
> - size = sizeof(*old_supply) * opp_table->regulator_count;
> + size = sizeof(*old_supply) * regulator_count;
> if (!old_supply)
> memset(data->old_opp.supplies, 0, size);
> else

--
viresh