diff mbox series

[v2,4/6] drm/panfrost: Set clocks on/off during system sleep on MediaTek SoCs

Message ID 20231102142643.75288-5-angelogioacchino.delregno@collabora.com (mailing list archive)
State New, archived
Headers show
Series drm/panfrost: Turn off clocks and regulators in PM | expand

Commit Message

AngeloGioacchino Del Regno Nov. 2, 2023, 2:26 p.m. UTC
All of the MediaTek SoCs supported by Panfrost can switch the clocks
off and on during system sleep to save some power without any user
experience penalty.

Measurements taken on multiple MediaTek SoCs show that adding this
will not prolong the time that is required to resume the system in
any meaningful way.

As an example, for MT8195 - a "before" with only runtime PM operations
(so, without turning on/off GPU clocks), and an "after" executing both
the system sleep .resume() handler and .runtime_resume() (so the time
refers to T_Resume + T_Runtime_Resume):

Average Panfrost-only system sleep resume time, before: ~28000ns
Average Panfrost-only system sleep resume time, after:  ~33500ns

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_drv.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Steven Price Nov. 8, 2023, 3:44 p.m. UTC | #1
On 02/11/2023 14:26, AngeloGioacchino Del Regno wrote:
> All of the MediaTek SoCs supported by Panfrost can switch the clocks
> off and on during system sleep to save some power without any user
> experience penalty.
> 
> Measurements taken on multiple MediaTek SoCs show that adding this
> will not prolong the time that is required to resume the system in
> any meaningful way.
> 
> As an example, for MT8195 - a "before" with only runtime PM operations
> (so, without turning on/off GPU clocks), and an "after" executing both
> the system sleep .resume() handler and .runtime_resume() (so the time
> refers to T_Resume + T_Runtime_Resume):
> 
> Average Panfrost-only system sleep resume time, before: ~28000ns
> Average Panfrost-only system sleep resume time, after:  ~33500ns
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

The change looks good:

Reviewed-by: Steven Price <steven.price@arm.com>

However it would be good to explicitly state (in the commit message)
which SoCs you personally have tested (for correctness), just in case we
find there are problems in the future with this on a particular SoC.

Steve

> ---
>  drivers/gpu/drm/panfrost/panfrost_drv.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 7cabf4e3d1f2..82f3c5fe9c58 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -734,6 +734,7 @@ static const struct panfrost_compatible mediatek_mt8183_b_data = {
>  	.supply_names = mediatek_mt8183_b_supplies,
>  	.num_pm_domains = ARRAY_SIZE(mediatek_mt8183_pm_domains),
>  	.pm_domain_names = mediatek_mt8183_pm_domains,
> +	.pm_features = BIT(GPU_PM_CLK_DIS),
>  };
>  
>  static const char * const mediatek_mt8186_pm_domains[] = { "core0", "core1" };
> @@ -742,6 +743,7 @@ static const struct panfrost_compatible mediatek_mt8186_data = {
>  	.supply_names = mediatek_mt8183_b_supplies,
>  	.num_pm_domains = ARRAY_SIZE(mediatek_mt8186_pm_domains),
>  	.pm_domain_names = mediatek_mt8186_pm_domains,
> +	.pm_features = BIT(GPU_PM_CLK_DIS),
>  };
>  
>  static const char * const mediatek_mt8192_supplies[] = { "mali", NULL };
> @@ -752,6 +754,7 @@ static const struct panfrost_compatible mediatek_mt8192_data = {
>  	.supply_names = mediatek_mt8192_supplies,
>  	.num_pm_domains = ARRAY_SIZE(mediatek_mt8192_pm_domains),
>  	.pm_domain_names = mediatek_mt8192_pm_domains,
> +	.pm_features = BIT(GPU_PM_CLK_DIS),
>  };
>  
>  static const struct of_device_id dt_match[] = {
diff mbox series

Patch

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 7cabf4e3d1f2..82f3c5fe9c58 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -734,6 +734,7 @@  static const struct panfrost_compatible mediatek_mt8183_b_data = {
 	.supply_names = mediatek_mt8183_b_supplies,
 	.num_pm_domains = ARRAY_SIZE(mediatek_mt8183_pm_domains),
 	.pm_domain_names = mediatek_mt8183_pm_domains,
+	.pm_features = BIT(GPU_PM_CLK_DIS),
 };
 
 static const char * const mediatek_mt8186_pm_domains[] = { "core0", "core1" };
@@ -742,6 +743,7 @@  static const struct panfrost_compatible mediatek_mt8186_data = {
 	.supply_names = mediatek_mt8183_b_supplies,
 	.num_pm_domains = ARRAY_SIZE(mediatek_mt8186_pm_domains),
 	.pm_domain_names = mediatek_mt8186_pm_domains,
+	.pm_features = BIT(GPU_PM_CLK_DIS),
 };
 
 static const char * const mediatek_mt8192_supplies[] = { "mali", NULL };
@@ -752,6 +754,7 @@  static const struct panfrost_compatible mediatek_mt8192_data = {
 	.supply_names = mediatek_mt8192_supplies,
 	.num_pm_domains = ARRAY_SIZE(mediatek_mt8192_pm_domains),
 	.pm_domain_names = mediatek_mt8192_pm_domains,
+	.pm_features = BIT(GPU_PM_CLK_DIS),
 };
 
 static const struct of_device_id dt_match[] = {