Argh sorry I messed up the rebase and this doesn't even build...
I'll send v13.
On Wed, Apr 21, 2021 at 8:19 AM Nicolas Boichat <drinkcat@xxxxxxxxxxxx> wrote:
>
> GPUs with more than a single regulator (e.g. G72 on MT8183) will
> require platform-specific handling for devfreq, for 2 reasons:
> 1. The opp core (drivers/opp/core.c:_generic_set_opp_regulator)
> does not support multiple regulators, so we'll need custom
> handlers.
> 2. Generally, platforms with 2 regulators have platform-specific
> constraints on how the voltages should be set (e.g.
> minimum/maximum voltage difference between them), so we
> should not just create generic handlers that simply
> change the voltages without taking care of those constraints.
>
> Disable devfreq for now on those GPUs.
>
> Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
> Reviewed-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
> Reviewed-by: Steven Price <steven.price@xxxxxxx>
> ---
>
> (no changes since v9)
>
> Changes in v9:
> - Explain why devfreq needs to be disabled for GPUs with >1
> regulators.
>
> Changes in v8:
> - Use DRM_DEV_INFO instead of ERROR
>
> Changes in v7:
> - Fix GPU ID in commit message
>
> Changes in v6:
> - devfreq: New change
>
> drivers/gpu/drm/panfrost/panfrost_devfreq.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 47d27e54a34f..aca3bb9a12e4 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -92,9 +92,19 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
> struct thermal_cooling_device *cooling;
> struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
>
> - ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
> - pfdev->comp->num_supplies);
> - if (ret) {
> + if (pfdev->comp->num_supplies > 1) {
> + /*
> + * GPUs with more than 1 supply require platform-specific handling:
> + * continue without devfreq
> + */
> + DRM_DEV_INFO(dev, "More than 1 supply is not supported yet\n");
> + return 0;
> + }
> +
> + opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
> + pfdev->comp->num_supplies);
> + if (IS_ERR(opp_table)) {
> + ret = PTR_ERR(opp_table);
> /* Continue if the optional regulator is missing */
> if (ret != -ENODEV) {
> DRM_DEV_ERROR(dev, "Couldn't set OPP regulators\n");
> --
> 2.31.1.368.gbe11c130af-goog
>
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