On 30/10/2023 13:22, AngeloGioacchino Del Regno wrote:
> Some platforms/SoCs can power off the GPU entirely by completely cutting
> off power, greatly enhancing battery time during system suspend: add a
> new pm_feature GPU_PM_VREG_OFF to allow turning off the GPU regulators
> during full suspend only on selected platforms.
>
> Signed-off-by: AngeloGioacchino Del Regno
> <angelogioacchino.delre...@collabora.com>
> ---
> drivers/gpu/drm/panfrost/panfrost_device.c | 19 ++++++++++++++++++-
> drivers/gpu/drm/panfrost/panfrost_device.h | 2 ++
> 2 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c
> b/drivers/gpu/drm/panfrost/panfrost_device.c
> index 2022ed76a620..51b22eb0971d 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> @@ -431,10 +431,21 @@ static int panfrost_device_resume(struct device *dev)
> struct panfrost_device *pfdev = dev_get_drvdata(dev);
> int ret;
>
> + if (pfdev->comp->pm_features & BIT(GPU_PM_VREG_OFF)) {
> + unsigned long freq = pfdev->pfdevfreq.fast_rate;
> + struct dev_pm_opp *opp;
> +
> + opp = dev_pm_opp_find_freq_ceil(dev, &freq);
> + if (IS_ERR(opp))
> + return PTR_ERR(opp);
> + dev_pm_opp_put(opp);
> + dev_pm_opp_set_opp(dev, opp);
These lines look the wrong way round - surely we want to hang onto the
reference until the set_opp call is made?
Steve
> + }
> +
> if (pfdev->comp->pm_features & BIT(GPU_PM_CLK_DIS)) {
> ret = clk_enable(pfdev->clock);
> if (ret)
> - return ret;
> + goto err_clk;
>
> if (pfdev->bus_clock) {
> ret = clk_enable(pfdev->bus_clock);
> @@ -455,6 +466,9 @@ static int panfrost_device_resume(struct device *dev)
> err_bus_clk:
> if (pfdev->comp->pm_features & BIT(GPU_PM_CLK_DIS))
> clk_disable(pfdev->clock);
> +err_clk:
> + if (pfdev->comp->pm_features & BIT(GPU_PM_VREG_OFF))
> + dev_pm_opp_set_opp(dev, NULL);
> return ret;
> }
>
> @@ -474,6 +488,9 @@ static int panfrost_device_suspend(struct device *dev)
> clk_disable(pfdev->bus_clock);
> }
>
> + if (pfdev->comp->pm_features & BIT(GPU_PM_VREG_OFF))
> + dev_pm_opp_set_opp(dev, NULL);
> +
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h
> b/drivers/gpu/drm/panfrost/panfrost_device.h
> index d7f179eb8ea3..0fc558db6bfd 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -28,9 +28,11 @@ struct panfrost_perfcnt;
> /**
> * enum panfrost_gpu_pm - Supported kernel power management features
> * @GPU_PM_CLK_DIS: Allow disabling clocks during system suspend
> + * @GPU_PM_VREG_OFF: Allow turning off regulators during system suspend
> */
> enum panfrost_gpu_pm {
> GPU_PM_CLK_DIS,
> + GPU_PM_VREG_OFF,
> };
>
> struct panfrost_features {
