Re: [PATCH] drm/lima: Fix dev_pm_opp_set_config in case of missing regulator

From: Viresh Kumar
Date: Wed Oct 26 2022 - 05:36:13 EST


On 26-10-22, 10:39, Erico Nunes wrote:
> Commit d8c32d3971e4 ("drm/lima: Migrate to dev_pm_opp_set_config()")
> introduced a regression as it may undo the clk_names setting in case
> the optional regulator is missing. This resulted in test and performance
> regressions with lima.
>
> Restore the old behavior where clk_names is set separately so it is not
> undone in case of a missing optional regulator.
>
> Fixes: d8c32d3971e4 ("drm/lima: Migrate to dev_pm_opp_set_config()")
> Signed-off-by: Erico Nunes <nunes.erico@xxxxxxxxx>
> ---
> drivers/gpu/drm/lima/lima_devfreq.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/lima/lima_devfreq.c b/drivers/gpu/drm/lima/lima_devfreq.c
> index 011be7ff51e1..9c8654934fea 100644
> --- a/drivers/gpu/drm/lima/lima_devfreq.c
> +++ b/drivers/gpu/drm/lima/lima_devfreq.c
> @@ -113,10 +113,12 @@ int lima_devfreq_init(struct lima_device *ldev)
> int ret;
> const char *regulator_names[] = { "mali", NULL };
> const char *clk_names[] = { "core", NULL };
> - struct dev_pm_opp_config config = {
> - .regulator_names = regulator_names,
> + struct dev_pm_opp_config config_clk_names = {
> .clk_names = clk_names,
> };
> + struct dev_pm_opp_config config_regulator_names = {
> + .regulator_names = regulator_names,
> + };
>
> if (!device_property_present(dev, "operating-points-v2"))
> /* Optional, continue without devfreq */
> @@ -124,7 +126,15 @@ int lima_devfreq_init(struct lima_device *ldev)
>
> spin_lock_init(&ldevfreq->lock);
>
> - ret = devm_pm_opp_set_config(dev, &config);
> + /*
> + * Set clk_names separately so it is not undone in case of
> + * a missing optional regulator.
> + */
> + ret = devm_pm_opp_set_config(dev, &config_clk_names);
> + if (ret)
> + return ret;
> +
> + ret = devm_pm_opp_set_config(dev, &config_regulator_names);

You can directly call devm_pm_opp_set_clkname() and
devm_pm_opp_set_regulators(), like it was done before my patch, for
single configurations. So basically a simple revert of my commit, with
additional comments you added above.

> if (ret) {
> /* Continue if the optional regulator is missing */
> if (ret != -ENODEV)
> --
> 2.37.3

--
viresh