2022-11-07 18:05:49

by Paul Cercueil

[permalink] [raw]
Subject: [PATCH 12/26] drm: etnaviv: Remove #ifdef guards for PM related functions

Use the RUNTIME_PM_OPS() and pm_ptr() macros to handle the
.runtime_suspend/.runtime_resume callbacks.

These macros allow the suspend and resume functions to be automatically
dropped by the compiler when CONFIG_PM is disabled, without having
to use #ifdef guards.

This has the advantage of always compiling these functions in,
independently of any Kconfig option. Thanks to that, bugs and other
regressions are subsequently easier to catch.

Some #ifdef CONFIG_PM guards were protecting simple statements, and were
also converted to "if (IS_ENABLED(CONFIG_PM))".

Note that this driver should probably use the
DEFINE_RUNTIME_DEV_PM_OPS() macro instead, which will provide
.suspend/.resume callbacks, pointing to pm_runtime_force_suspend() and
pm_runtime_force_resume() respectively; unless those callbacks really
aren't needed.

Signed-off-by: Paul Cercueil <[email protected]>
---
Cc: Lucas Stach <[email protected]>
Cc: Russell King <[email protected]>
Cc: Christian Gmeiner <[email protected]>
Cc: [email protected]
---
drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 30 +++++++++++----------------
1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index 37018bc55810..e9a5444ec1c7 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1605,7 +1605,6 @@ static int etnaviv_gpu_hw_suspend(struct etnaviv_gpu *gpu)
return etnaviv_gpu_clk_disable(gpu);
}

-#ifdef CONFIG_PM
static int etnaviv_gpu_hw_resume(struct etnaviv_gpu *gpu)
{
int ret;
@@ -1621,7 +1620,6 @@ static int etnaviv_gpu_hw_resume(struct etnaviv_gpu *gpu)

return 0;
}
-#endif

static int
etnaviv_gpu_cooling_get_max_state(struct thermal_cooling_device *cdev,
@@ -1689,11 +1687,10 @@ static int etnaviv_gpu_bind(struct device *dev, struct device *master,
if (ret)
goto out_workqueue;

-#ifdef CONFIG_PM
- ret = pm_runtime_get_sync(gpu->dev);
-#else
- ret = etnaviv_gpu_clk_enable(gpu);
-#endif
+ if (IS_ENABLED(CONFIG_PM))
+ ret = pm_runtime_get_sync(gpu->dev);
+ else
+ ret = etnaviv_gpu_clk_enable(gpu);
if (ret < 0)
goto out_sched;

@@ -1737,12 +1734,12 @@ static void etnaviv_gpu_unbind(struct device *dev, struct device *master,

etnaviv_sched_fini(gpu);

-#ifdef CONFIG_PM
- pm_runtime_get_sync(gpu->dev);
- pm_runtime_put_sync_suspend(gpu->dev);
-#else
- etnaviv_gpu_hw_suspend(gpu);
-#endif
+ if (IS_ENABLED(CONFIG_PM)) {
+ pm_runtime_get_sync(gpu->dev);
+ pm_runtime_put_sync_suspend(gpu->dev);
+ } else {
+ etnaviv_gpu_hw_suspend(gpu);
+ }

if (gpu->mmu_context)
etnaviv_iommu_context_put(gpu->mmu_context);
@@ -1856,7 +1853,6 @@ static int etnaviv_gpu_platform_remove(struct platform_device *pdev)
return 0;
}

-#ifdef CONFIG_PM
static int etnaviv_gpu_rpm_suspend(struct device *dev)
{
struct etnaviv_gpu *gpu = dev_get_drvdata(dev);
@@ -1899,18 +1895,16 @@ static int etnaviv_gpu_rpm_resume(struct device *dev)

return 0;
}
-#endif

static const struct dev_pm_ops etnaviv_gpu_pm_ops = {
- SET_RUNTIME_PM_OPS(etnaviv_gpu_rpm_suspend, etnaviv_gpu_rpm_resume,
- NULL)
+ RUNTIME_PM_OPS(etnaviv_gpu_rpm_suspend, etnaviv_gpu_rpm_resume, NULL)
};

struct platform_driver etnaviv_gpu_driver = {
.driver = {
.name = "etnaviv-gpu",
.owner = THIS_MODULE,
- .pm = &etnaviv_gpu_pm_ops,
+ .pm = pm_ptr(&etnaviv_gpu_pm_ops),
.of_match_table = etnaviv_gpu_match,
},
.probe = etnaviv_gpu_platform_probe,
--
2.35.1



2022-11-07 18:40:08

by Lucas Stach

[permalink] [raw]
Subject: Re: [PATCH 12/26] drm: etnaviv: Remove #ifdef guards for PM related functions

Am Montag, dem 07.11.2022 um 17:52 +0000 schrieb Paul Cercueil:
> Use the RUNTIME_PM_OPS() and pm_ptr() macros to handle the
> .runtime_suspend/.runtime_resume callbacks.
>
> These macros allow the suspend and resume functions to be automatically
> dropped by the compiler when CONFIG_PM is disabled, without having
> to use #ifdef guards.
>
> This has the advantage of always compiling these functions in,
> independently of any Kconfig option. Thanks to that, bugs and other
> regressions are subsequently easier to catch.
>
> Some #ifdef CONFIG_PM guards were protecting simple statements, and were
> also converted to "if (IS_ENABLED(CONFIG_PM))".
>
Reasoning and the change itself look good.

> Note that this driver should probably use the
> DEFINE_RUNTIME_DEV_PM_OPS() macro instead, which will provide
> .suspend/.resume callbacks, pointing to pm_runtime_force_suspend() and
> pm_runtime_force_resume() respectively; unless those callbacks really
> aren't needed.

This however isn't true, specifically this driver can _not_ use
pm_runtime_force_suspend, as the GPU can't be forced into suspend by
calling the rpm callback. A real suspend implementation would first
need to make sure the GPU finished working on the current queued jobs,
only then it would be able to power it down via the rpm suspend
callback.

Regards,
Lucas

>
> Signed-off-by: Paul Cercueil <[email protected]>
> ---
> Cc: Lucas Stach <[email protected]>
> Cc: Russell King <[email protected]>
> Cc: Christian Gmeiner <[email protected]>
> Cc: [email protected]
> ---
> drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 30 +++++++++++----------------
> 1 file changed, 12 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> index 37018bc55810..e9a5444ec1c7 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> @@ -1605,7 +1605,6 @@ static int etnaviv_gpu_hw_suspend(struct etnaviv_gpu *gpu)
> return etnaviv_gpu_clk_disable(gpu);
> }
>
> -#ifdef CONFIG_PM
> static int etnaviv_gpu_hw_resume(struct etnaviv_gpu *gpu)
> {
> int ret;
> @@ -1621,7 +1620,6 @@ static int etnaviv_gpu_hw_resume(struct etnaviv_gpu *gpu)
>
> return 0;
> }
> -#endif
>
> static int
> etnaviv_gpu_cooling_get_max_state(struct thermal_cooling_device *cdev,
> @@ -1689,11 +1687,10 @@ static int etnaviv_gpu_bind(struct device *dev, struct device *master,
> if (ret)
> goto out_workqueue;
>
> -#ifdef CONFIG_PM
> - ret = pm_runtime_get_sync(gpu->dev);
> -#else
> - ret = etnaviv_gpu_clk_enable(gpu);
> -#endif
> + if (IS_ENABLED(CONFIG_PM))
> + ret = pm_runtime_get_sync(gpu->dev);
> + else
> + ret = etnaviv_gpu_clk_enable(gpu);
> if (ret < 0)
> goto out_sched;
>
> @@ -1737,12 +1734,12 @@ static void etnaviv_gpu_unbind(struct device *dev, struct device *master,
>
> etnaviv_sched_fini(gpu);
>
> -#ifdef CONFIG_PM
> - pm_runtime_get_sync(gpu->dev);
> - pm_runtime_put_sync_suspend(gpu->dev);
> -#else
> - etnaviv_gpu_hw_suspend(gpu);
> -#endif
> + if (IS_ENABLED(CONFIG_PM)) {
> + pm_runtime_get_sync(gpu->dev);
> + pm_runtime_put_sync_suspend(gpu->dev);
> + } else {
> + etnaviv_gpu_hw_suspend(gpu);
> + }
>
> if (gpu->mmu_context)
> etnaviv_iommu_context_put(gpu->mmu_context);
> @@ -1856,7 +1853,6 @@ static int etnaviv_gpu_platform_remove(struct platform_device *pdev)
> return 0;
> }
>
> -#ifdef CONFIG_PM
> static int etnaviv_gpu_rpm_suspend(struct device *dev)
> {
> struct etnaviv_gpu *gpu = dev_get_drvdata(dev);
> @@ -1899,18 +1895,16 @@ static int etnaviv_gpu_rpm_resume(struct device *dev)
>
> return 0;
> }
> -#endif
>
> static const struct dev_pm_ops etnaviv_gpu_pm_ops = {
> - SET_RUNTIME_PM_OPS(etnaviv_gpu_rpm_suspend, etnaviv_gpu_rpm_resume,
> - NULL)
> + RUNTIME_PM_OPS(etnaviv_gpu_rpm_suspend, etnaviv_gpu_rpm_resume, NULL)
> };
>
> struct platform_driver etnaviv_gpu_driver = {
> .driver = {
> .name = "etnaviv-gpu",
> .owner = THIS_MODULE,
> - .pm = &etnaviv_gpu_pm_ops,
> + .pm = pm_ptr(&etnaviv_gpu_pm_ops),
> .of_match_table = etnaviv_gpu_match,
> },
> .probe = etnaviv_gpu_platform_probe,



2022-11-07 22:01:36

by Paul Cercueil

[permalink] [raw]
Subject: Re: [PATCH 12/26] drm: etnaviv: Remove #ifdef guards for PM related functions

Hi Lucas,

Le lun. 7 nov. 2022 ? 19:07:32 +0100, Lucas Stach
<[email protected]> a ?crit :
> Am Montag, dem 07.11.2022 um 17:52 +0000 schrieb Paul Cercueil:
>> Use the RUNTIME_PM_OPS() and pm_ptr() macros to handle the
>> .runtime_suspend/.runtime_resume callbacks.
>>
>> These macros allow the suspend and resume functions to be
>> automatically
>> dropped by the compiler when CONFIG_PM is disabled, without having
>> to use #ifdef guards.
>>
>> This has the advantage of always compiling these functions in,
>> independently of any Kconfig option. Thanks to that, bugs and other
>> regressions are subsequently easier to catch.
>>
>> Some #ifdef CONFIG_PM guards were protecting simple statements, and
>> were
>> also converted to "if (IS_ENABLED(CONFIG_PM))".
>>
> Reasoning and the change itself look good.

That's an ack? :)

>> Note that this driver should probably use the
>> DEFINE_RUNTIME_DEV_PM_OPS() macro instead, which will provide
>> .suspend/.resume callbacks, pointing to pm_runtime_force_suspend()
>> and
>> pm_runtime_force_resume() respectively; unless those callbacks
>> really
>> aren't needed.
>
> This however isn't true, specifically this driver can _not_ use
> pm_runtime_force_suspend, as the GPU can't be forced into suspend by
> calling the rpm callback. A real suspend implementation would first
> need to make sure the GPU finished working on the current queued jobs,
> only then it would be able to power it down via the rpm suspend
> callback.

Understood. I'll remove this paragraph if I have to V2.

Cheers,
-Paul

>>
>> Signed-off-by: Paul Cercueil <[email protected]>
>> ---
>> Cc: Lucas Stach <[email protected]>
>> Cc: Russell King <[email protected]>
>> Cc: Christian Gmeiner <[email protected]>
>> Cc: [email protected]
>> ---
>> drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 30
>> +++++++++++----------------
>> 1 file changed, 12 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
>> b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
>> index 37018bc55810..e9a5444ec1c7 100644
>> --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
>> @@ -1605,7 +1605,6 @@ static int etnaviv_gpu_hw_suspend(struct
>> etnaviv_gpu *gpu)
>> return etnaviv_gpu_clk_disable(gpu);
>> }
>>
>> -#ifdef CONFIG_PM
>> static int etnaviv_gpu_hw_resume(struct etnaviv_gpu *gpu)
>> {
>> int ret;
>> @@ -1621,7 +1620,6 @@ static int etnaviv_gpu_hw_resume(struct
>> etnaviv_gpu *gpu)
>>
>> return 0;
>> }
>> -#endif
>>
>> static int
>> etnaviv_gpu_cooling_get_max_state(struct thermal_cooling_device
>> *cdev,
>> @@ -1689,11 +1687,10 @@ static int etnaviv_gpu_bind(struct device
>> *dev, struct device *master,
>> if (ret)
>> goto out_workqueue;
>>
>> -#ifdef CONFIG_PM
>> - ret = pm_runtime_get_sync(gpu->dev);
>> -#else
>> - ret = etnaviv_gpu_clk_enable(gpu);
>> -#endif
>> + if (IS_ENABLED(CONFIG_PM))
>> + ret = pm_runtime_get_sync(gpu->dev);
>> + else
>> + ret = etnaviv_gpu_clk_enable(gpu);
>> if (ret < 0)
>> goto out_sched;
>>
>> @@ -1737,12 +1734,12 @@ static void etnaviv_gpu_unbind(struct
>> device *dev, struct device *master,
>>
>> etnaviv_sched_fini(gpu);
>>
>> -#ifdef CONFIG_PM
>> - pm_runtime_get_sync(gpu->dev);
>> - pm_runtime_put_sync_suspend(gpu->dev);
>> -#else
>> - etnaviv_gpu_hw_suspend(gpu);
>> -#endif
>> + if (IS_ENABLED(CONFIG_PM)) {
>> + pm_runtime_get_sync(gpu->dev);
>> + pm_runtime_put_sync_suspend(gpu->dev);
>> + } else {
>> + etnaviv_gpu_hw_suspend(gpu);
>> + }
>>
>> if (gpu->mmu_context)
>> etnaviv_iommu_context_put(gpu->mmu_context);
>> @@ -1856,7 +1853,6 @@ static int etnaviv_gpu_platform_remove(struct
>> platform_device *pdev)
>> return 0;
>> }
>>
>> -#ifdef CONFIG_PM
>> static int etnaviv_gpu_rpm_suspend(struct device *dev)
>> {
>> struct etnaviv_gpu *gpu = dev_get_drvdata(dev);
>> @@ -1899,18 +1895,16 @@ static int etnaviv_gpu_rpm_resume(struct
>> device *dev)
>>
>> return 0;
>> }
>> -#endif
>>
>> static const struct dev_pm_ops etnaviv_gpu_pm_ops = {
>> - SET_RUNTIME_PM_OPS(etnaviv_gpu_rpm_suspend,
>> etnaviv_gpu_rpm_resume,
>> - NULL)
>> + RUNTIME_PM_OPS(etnaviv_gpu_rpm_suspend, etnaviv_gpu_rpm_resume,
>> NULL)
>> };
>>
>> struct platform_driver etnaviv_gpu_driver = {
>> .driver = {
>> .name = "etnaviv-gpu",
>> .owner = THIS_MODULE,
>> - .pm = &etnaviv_gpu_pm_ops,
>> + .pm = pm_ptr(&etnaviv_gpu_pm_ops),
>> .of_match_table = etnaviv_gpu_match,
>> },
>> .probe = etnaviv_gpu_platform_probe,
>
>