Re: [PATCH] venus: pm_helpers: Control core power domain manually

[Fritz Koenig]

On Fri, Jan 8, 2021 at 11:23 PM Stanimir Varbanov
<stanimir.varbanov@xxxxxxxxxx> wrote:
>
> Presently we use device_link to control core power domain. But this
> leads to issues because the genpd doesn't guarantee synchronous on/off
> for supplier devices. Switch to manually control by pmruntime calls.
>
> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
> ---
>  drivers/media/platform/qcom/venus/core.h      |  1 -
>  .../media/platform/qcom/venus/pm_helpers.c    | 36 ++++++++++---------
>  2 files changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
> index dfc13b2f371f..74d9fd3d51cc 100644
> --- a/drivers/media/platform/qcom/venus/core.h
> +++ b/drivers/media/platform/qcom/venus/core.h
> @@ -128,7 +128,6 @@ struct venus_core {
>         struct icc_path *cpucfg_path;
>         struct opp_table *opp_table;
>         bool has_opp_table;
> -       struct device_link *pd_dl_venus;

remove from comment at start of struct as well.
 * @pd_dl_venus: pmdomain device-link for venus domain

The patch gives huge improvements in encoder stability!

Tested-by: Fritz Koenig <frkoenig@xxxxxxxxxxxx>



>         struct device *pmdomains[VIDC_PMDOMAINS_NUM_MAX];
>         struct device_link *opp_dl_venus;
>         struct device *opp_pmdomain;
> diff --git a/drivers/media/platform/qcom/venus/pm_helpers.c b/drivers/media/platform/qcom/venus/pm_helpers.c
> index 94219a3093cb..e0338932a720 100644
> --- a/drivers/media/platform/qcom/venus/pm_helpers.c
> +++ b/drivers/media/platform/qcom/venus/pm_helpers.c
> @@ -774,13 +774,6 @@ static int vcodec_domains_get(struct device *dev)
>                 core->pmdomains[i] = pd;
>         }
>
> -       core->pd_dl_venus = device_link_add(dev, core->pmdomains[0],
> -                                           DL_FLAG_PM_RUNTIME |
> -                                           DL_FLAG_STATELESS |
> -                                           DL_FLAG_RPM_ACTIVE);
> -       if (!core->pd_dl_venus)
> -               return -ENODEV;
> -
>  skip_pmdomains:
>         if (!core->has_opp_table)
>                 return 0;
> @@ -807,14 +800,12 @@ static int vcodec_domains_get(struct device *dev)
>  opp_dl_add_err:
>         dev_pm_opp_detach_genpd(core->opp_table);
>  opp_attach_err:
> -       if (core->pd_dl_venus) {
> -               device_link_del(core->pd_dl_venus);
> -               for (i = 0; i < res->vcodec_pmdomains_num; i++) {
> -                       if (IS_ERR_OR_NULL(core->pmdomains[i]))
> -                               continue;
> -                       dev_pm_domain_detach(core->pmdomains[i], true);
> -               }
> +       for (i = 0; i < res->vcodec_pmdomains_num; i++) {
> +               if (IS_ERR_OR_NULL(core->pmdomains[i]))
> +                       continue;
> +               dev_pm_domain_detach(core->pmdomains[i], true);
>         }
> +
>         return ret;
>  }
>
> @@ -827,9 +818,6 @@ static void vcodec_domains_put(struct device *dev)
>         if (!res->vcodec_pmdomains_num)
>                 goto skip_pmdomains;
>
> -       if (core->pd_dl_venus)
> -               device_link_del(core->pd_dl_venus);
> -
>         for (i = 0; i < res->vcodec_pmdomains_num; i++) {
>                 if (IS_ERR_OR_NULL(core->pmdomains[i]))
>                         continue;
> @@ -917,16 +905,30 @@ static void core_put_v4(struct device *dev)
>  static int core_power_v4(struct device *dev, int on)
>  {
>         struct venus_core *core = dev_get_drvdata(dev);
> +       struct device *pmctrl = core->pmdomains[0];
>         int ret = 0;
>
>         if (on == POWER_ON) {
> +               if (pmctrl) {
> +                       ret = pm_runtime_get_sync(pmctrl);
> +                       if (ret < 0) {
> +                               pm_runtime_put_noidle(pmctrl);
> +                               return ret;
> +                       }
> +               }
> +
>                 ret = core_clks_enable(core);
> +               if (ret < 0 && pmctrl)
> +                       pm_runtime_put_sync(pmctrl);
>         } else {
>                 /* Drop the performance state vote */
>                 if (core->opp_pmdomain)
>                         dev_pm_opp_set_rate(dev, 0);
>
>                 core_clks_disable(core);
> +
> +               if (pmctrl)
> +                       pm_runtime_put_sync(pmctrl);
>         }
>
>         return ret;
> --
> 2.17.1
>