[RFC 2/2] drm/amd/pm: Add support for reacting to platform profile notification
Lazar, Lijo
lijo.lazar at amd.com
Thu Nov 11 04:53:35 UTC 2021
On 11/10/2021 11:01 PM, Limonciello, Mario wrote:
> [Public]
>
>> I don't think we want to force the performance level. This interface
> forces various fixed clock configurations for debugging and profiling.
>
> Ah got it.
>
>>I think what we'd want to select here is the power profile (see
> amdgpu_set_pp_power_profile_mode()). For this interface you can
> select various profiles (BOOTUP_DEFAULT, 3D_FULL_SCREEN, POWER_SAVING,
> VIDEO, VR, COMPUTE, etc.). These still use dynamic power management,
> but they adjust the heuristics used by the GPU to select power states
> so the GPU performance ramps up/down more or less aggressively.
>
> Which profile mapping you think make sense?
>
> My guess would be:
>
> “BOOTUP_DEFAULT” for balanced
>
> “POWER_SAVING” for low-power
>
> “3D_FULL_SCREEN” for performance
>
> Since recently we removed that interface for YC, and some earlier APUs
> don’t do as much with it.
>
> So I wonder if this is only really valuable to do this callback for !APU.
>
>>I feel it's better to leave to platform vendors. For ex: for APU cases
> they may have implementations in which their BIOSes talk to PMFW and
> this might be driving something else here.
>
> Even if changing the heuristic for workload as Alex suggested?
>
Yes. I think this is meant to be BIOS driven for APU platforms and AMD
APU + AMD dGPU with smartshift.
>>Also, not sure how to handle a case like, say a laptop with Intel CPU
> and AMD dgpu.
>
> I was actually thinking this approach where there are platform profile
> callbacks is best because of that specifically.
>
> It would allow an Intel CPU system to have a platform profile driver
> implemented by the OEM, but then still notify amdgpu dGPU to tune for
> power saving or performance workload.
>
After seeing that this is coming under ACPI, I thought the intention is
to have this driven by firmware primarily. The purpose of platform
driver itself could be to optimize for those power profiles and while
doing that it should have considered all the components in the whole
platform (assuming platform driver testing covers the behavior of these
modes on a particular platform).
I am not sure if it's appropriate for another driver to plug-in to this
automatically and tinker an 'expected-to-be-well-tuned' setting by the
platform driver. The modes selected by another driver may or may not
match with the conditions assumed by platform driver - for ex: some
profile could mean fans running quieter with EC control and then the
profile chosen by another driver could disturb that intended setting.
Thanks,
Lijo
> *From:* Lazar, Lijo <Lijo.Lazar at amd.com>
> *Sent:* Wednesday, November 10, 2021 10:05
> *To:* Alex Deucher <alexdeucher at gmail.com>; Limonciello, Mario
> <Mario.Limonciello at amd.com>
> *Cc:* amd-gfx list <amd-gfx at lists.freedesktop.org>
> *Subject:* Re: [RFC 2/2] drm/amd/pm: Add support for reacting to
> platform profile notification
>
> [Public]
>
> I feel it's better to leave to platform vendors. For ex: for APU cases
> they may have implementations in which their BIOSes talk to PMFW and
> this might be driving something else here.
>
> Also, not sure how to handle a case like, say a laptop with Intel CPU
> and AMD dgpu.
>
> Thanks,
> Lijo
>
> ------------------------------------------------------------------------
>
> *From:* amd-gfx <amd-gfx-bounces at lists.freedesktop.org
> <mailto:amd-gfx-bounces at lists.freedesktop.org>> on behalf of Alex
> Deucher <alexdeucher at gmail.com <mailto:alexdeucher at gmail.com>>
> *Sent:* Wednesday, 10 November 2021, 8:44 pm
> *To:* Limonciello, Mario
> *Cc:* amd-gfx list
> *Subject:* Re: [RFC 2/2] drm/amd/pm: Add support for reacting to
> platform profile notification
>
> On Wed, Nov 10, 2021 at 1:24 AM Mario Limonciello
> <mario.limonciello at amd.com <mailto:mario.limonciello at amd.com>> wrote:
> >
> > Various drivers provide platform profile support to let users set a hint
> > in their GUI whether they want to run in a high performance, low battery
> > life or balanced configuration.
> >
> > Drivers that provide this typically work with the firmware on their
> system
> > to configure hardware. In the case of AMDGPU however, the notification
> > path doesn't come through firmware and can instead be provided directly
> > to the driver from a notification chain.
> >
> > Use the information of the newly selected profile to tweak
> > `dpm_force_performance_level` to that profile IFF the user hasn't
> manually
> > selected `manual` or any other `profile_*` options.
>
> I don't think we want to force the performance level. This interface
> forces various fixed clock configurations for debugging and profiling.
> I think what we'd want to select here is the power profile (see
> amdgpu_set_pp_power_profile_mode()). For this interface you can
> select various profiles (BOOTUP_DEFAULT, 3D_FULL_SCREEN, POWER_SAVING,
> VIDEO, VR, COMPUTE, etc.). These still use dynamic power management,
> but they adjust the heuristics used by the GPU to select power states
> so the GPU performance ramps up/down more or less aggressively.
>
> Alex
>
> >
> > Signed-off-by: Mario Limonciello <mario.limonciello at amd.com
> <mailto:mario.limonciello at amd.com>>
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 +
> > drivers/gpu/drm/amd/pm/amdgpu_pm.c | 105 +++++++++++++++++++++++-----
> > 2 files changed, 90 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > index b85b67a88a3d..27b0be23b6ac 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > @@ -1097,6 +1097,9 @@ struct amdgpu_device {
> >
> > struct amdgpu_reset_control *reset_cntl;
> > uint32_t
> ip_versions[HW_ID_MAX][HWIP_MAX_INSTANCE];
> > +
> > + /* platform profile notifications */
> > + struct notifier_block platform_profile_notifier;
> > };
> >
> > static inline struct amdgpu_device *drm_to_adev(struct drm_device *ddev)
> > diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> > index 41472ed99253..33fc52b90d4c 100644
> > --- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> > +++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> > @@ -32,6 +32,7 @@
> > #include <linux/hwmon.h>
> > #include <linux/hwmon-sysfs.h>
> > #include <linux/nospec.h>
> > +#include <linux/platform_profile.h>
> > #include <linux/pm_runtime.h>
> > #include <asm/processor.h>
> > #include "hwmgr.h"
> > @@ -200,6 +201,33 @@ static ssize_t amdgpu_set_power_dpm_state(struct
> device *dev,
> > return count;
> > }
> >
> > +static int amdgpu_get_forced_level(struct device *dev, enum
> amd_dpm_forced_level *level)
> > +{
> > + struct drm_device *ddev = dev_get_drvdata(dev);
> > + struct amdgpu_device *adev = drm_to_adev(ddev);
> > + int ret;
> > +
> > + if (amdgpu_in_reset(adev))
> > + return -EPERM;
> > + if (adev->in_suspend && !adev->in_runpm)
> > + return -EPERM;
> > +
> > + ret = pm_runtime_get_sync(ddev->dev);
> > + if (ret < 0) {
> > + pm_runtime_put_autosuspend(ddev->dev);
> > + return ret;
> > + }
> > +
> > + if (adev->powerplay.pp_funcs->get_performance_level)
> > + *level = amdgpu_dpm_get_performance_level(adev);
> > + else
> > + *level = adev->pm.dpm.forced_level;
> > +
> > + pm_runtime_mark_last_busy(ddev->dev);
> > + pm_runtime_put_autosuspend(ddev->dev);
> > +
> > + return 0;
> > +}
> >
> > /**
> > * DOC: power_dpm_force_performance_level
> > @@ -264,29 +292,13 @@ static ssize_t
> amdgpu_get_power_dpm_force_performance_level(struct device *dev,
> > struct
> device_attribute *attr,
> > char *buf)
> > {
> > - struct drm_device *ddev = dev_get_drvdata(dev);
> > - struct amdgpu_device *adev = drm_to_adev(ddev);
> > enum amd_dpm_forced_level level = 0xff;
> > int ret;
> >
> > - if (amdgpu_in_reset(adev))
> > - return -EPERM;
> > - if (adev->in_suspend && !adev->in_runpm)
> > - return -EPERM;
> > + ret = amdgpu_get_forced_level(dev, &level);
> >
> > - ret = pm_runtime_get_sync(ddev->dev);
> > - if (ret < 0) {
> > - pm_runtime_put_autosuspend(ddev->dev);
> > + if (ret < 0)
> > return ret;
> > - }
> > -
> > - if (adev->powerplay.pp_funcs->get_performance_level)
> > - level = amdgpu_dpm_get_performance_level(adev);
> > - else
> > - level = adev->pm.dpm.forced_level;
> > -
> > - pm_runtime_mark_last_busy(ddev->dev);
> > - pm_runtime_put_autosuspend(ddev->dev);
> >
> > return sysfs_emit(buf, "%s\n",
> > (level == AMD_DPM_FORCED_LEVEL_AUTO) ? "auto" :
> > @@ -405,6 +417,59 @@ static ssize_t
> amdgpu_set_power_dpm_force_performance_level(struct device *dev,
> > return count;
> > }
> >
> > +static void amdgpu_update_profile(struct device *dev, enum
> platform_profile_option *profile)
> > +{
> > + enum amd_dpm_forced_level level;
> > + const char *str;
> > + int ret;
> > +
> > + ret = amdgpu_get_forced_level(dev, &level);
> > + if (ret < 0)
> > + return;
> > +
> > + /* only update profile if we're in fixed modes right now that
> need updating */
> > + switch (level) {
> > + case AMD_DPM_FORCED_LEVEL_LOW:
> > + if (*profile < PLATFORM_PROFILE_BALANCED)
> > + return;
> > + break;
> > + case AMD_DPM_FORCED_LEVEL_HIGH:
> > + if (*profile > PLATFORM_PROFILE_BALANCED)
> > + return;
> > + break;
> > + case AMD_DPM_FORCED_LEVEL_AUTO:
> > + if (*profile == PLATFORM_PROFILE_BALANCED)
> > + return;
> > + break;
> > + default:
> > + dev_dbg(dev, "refusing to update amdgpu profile from
> %d\n", level);
> > + return;
> > + }
> > + if (*profile > PLATFORM_PROFILE_BALANCED)
> > + str = "high";
> > + else if (*profile < PLATFORM_PROFILE_BALANCED)
> > + str = "low";
> > + else
> > + str = "auto";
> > +
> > + dev_dbg(dev, "updating platform profile to %s\n", str);
> > + amdgpu_set_power_dpm_force_performance_level(dev, NULL, str, 0);
> > +}
> > +
> > +static int amdgpu_platform_profile_notifier_call(struct
> notifier_block *nb,
> > + unsigned long
> action, void *data)
> > +{
> > + if (action == PLATFORM_PROFILE_CHANGED) {
> > + enum platform_profile_option *profile = data;
> > + struct amdgpu_device *adev;
> > +
> > + adev = container_of(nb, struct amdgpu_device,
> platform_profile_notifier);
> > + amdgpu_update_profile(adev->dev, profile);
> > + }
> > +
> > + return NOTIFY_OK;
> > +}
> > +
> > static ssize_t amdgpu_get_pp_num_states(struct device *dev,
> > struct device_attribute *attr,
> > char *buf)
> > @@ -3506,6 +3571,9 @@ int amdgpu_pm_sysfs_init(struct amdgpu_device
> *adev)
> > if (ret)
> > return ret;
> >
> > + adev->platform_profile_notifier.notifier_call =
> amdgpu_platform_profile_notifier_call;
> > +
> platform_profile_register_notifier(&adev->platform_profile_notifier);
> > +
> > adev->pm.sysfs_initialized = true;
> >
> > return 0;
> > @@ -3519,6 +3587,7 @@ void amdgpu_pm_sysfs_fini(struct amdgpu_device
> *adev)
> > if (adev->pm.int_hwmon_dev)
> > hwmon_device_unregister(adev->pm.int_hwmon_dev);
> >
> > +
> platform_profile_unregister_notifier(&adev->platform_profile_notifier);
> > amdgpu_device_attr_remove_groups(adev, &adev->pm.pm_attr_list);
> > }
> >
> > --
> > 2.25.1
> >
>
More information about the amd-gfx
mailing list