[PATCH 13/15] platform/x86/amd/pmf: Add PMF-AMDGPU set interface

Hans de Goede hdegoede at redhat.com
Tue Sep 26 12:56:26 UTC 2023


Hi,

On 9/26/23 13:24, Shyam Sundar S K wrote:
> Hi Hans,
> 
> On 9/26/2023 4:05 PM, Hans de Goede wrote:
>> Hi,
>>
>> On 9/22/23 19:50, Shyam Sundar S K wrote:
>>> For the Smart PC Solution to fully work, it has to enact to the actions
>>> coming from TA. Add the initial code path for set interface to AMDGPU.
>>>
>>> Co-developed-by: Mario Limonciello <mario.limonciello at amd.com>
>>> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
>>> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k at amd.com>
>>> ---
>>>  drivers/gpu/drm/amd/amdgpu/amdgpu_pmf.c | 21 +++++++++++++++++++++
>>>  drivers/platform/x86/amd/pmf/pmf.h      |  2 ++
>>>  drivers/platform/x86/amd/pmf/tee-if.c   | 19 +++++++++++++++++--
>>>  include/linux/amd-pmf-io.h              |  1 +
>>>  4 files changed, 41 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pmf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pmf.c
>>> index 232d11833ddc..5c567bff0548 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pmf.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pmf.c
>>> @@ -68,3 +68,24 @@ int amd_pmf_get_gfx_data(struct amd_gpu_pmf_data *pmf)
>>>  	return 0;
>>>  }
>>>  EXPORT_SYMBOL_GPL(amd_pmf_get_gfx_data);
>>> +
>>> +int amd_pmf_set_gfx_data(struct amd_gpu_pmf_data *pmf)
>>> +{
>>> +	struct drm_device *drm_dev = pci_get_drvdata(pmf->gpu_dev);
>>> +	struct amdgpu_device *adev = drm_to_adev(drm_dev);
>>> +	struct backlight_device *bd;
>>> +
>>> +	if (!(adev->flags & AMD_IS_APU)) {
>>> +		DRM_ERROR("PMF-AMDGPU interface not supported\n");
>>> +		return -ENODEV;
>>> +	}
>>> +
>>> +	bd = backlight_device_get_by_type(BACKLIGHT_RAW);
>>> +	if (!bd)
>>> +		return -ENODEV;
>>
>> This assumes that the backlight is always controller by the amdgpu's
>> native backlight driver, but it might e.g. also be handled by
>> eacpi-video or by nvidia_wmi_ec_backlight (when using an AMD APU +
>> nvidia dgpu).
> 
> PMF is meant for AMD APUs(atleast for now) and the _HID will only be
> made visible if its AMD laptop. So using amdgpu's native BACKLIGHT_RAW
> should be safe, right?

Users can pass say acpi_backlight=video and use the acpi_video
driver for backlight control instead of the native GPU backlight
control.

> 
>>
>> For now what should be done here is to call acpi_video_get_backlight_type()
>> and then translate the return value from this into a backlight-type:
>>
>>         acpi_backlight_video		-> BACKLIGHT_FIRMWARE
>>         acpi_backlight_vendor,		-> BACKLIGHT_PLATFORM
>>         acpi_backlight_native,		-> BACKLIGHT_RAW
>>         acpi_backlight_nvidia_wmi_ec,	-> BACKLIGHT_FIRMWARE
>>         acpi_backlight_apple_gmux,	-> BACKLIGHT_PLATFORM
>>
> 
> I can add this change in the v2, do you insist on this?

Insist is a strong word, but I think that it is a good idea to have
this. Evenutally it looks like this code will need to either integrate with
the drm drivers lot more; or the drm core needs to export some special
hooks for this which the PMF code can then call.

Actually thinking more about this, I think that the right thing to do
here is make some code register brightness control as a cooling device
(which I think is already done in some cases) and then have the PMF
code use the cooling-device APIs for this.

IMHO that would be a much cleaner solution then this hack.

Regards,

Hans



> 
> Thanks,
> Shyam
> 
>> Also I'm worried about probe order here, this code currently assumes
>> that the GPU or other backlight driver has loaded before this runs,
>> which is not necessarily the case.
>>
>> I think that if the backlight_device_get_by_type() fails this
>> should be retried say every 10 seconds from some delayed workqueue
>> for at least a couple of minutes after boot.
>>
>> Regards,
>>
>> Hans
>>
>>
>>
>>
>>> +
>>> +	backlight_device_set_brightness(bd, pmf->brightness);
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(amd_pmf_set_gfx_data);
>>> diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h
>>> index 9032df4ba48a..ce89cc0daa5a 100644
>>> --- a/drivers/platform/x86/amd/pmf/pmf.h
>>> +++ b/drivers/platform/x86/amd/pmf/pmf.h
>>> @@ -73,6 +73,7 @@
>>>  #define PMF_POLICY_STT_SKINTEMP_APU				7
>>>  #define PMF_POLICY_STT_SKINTEMP_HS2				8
>>>  #define PMF_POLICY_SYSTEM_STATE					9
>>> +#define PMF_POLICY_DISPLAY_BRIGHTNESS				12
>>>  #define PMF_POLICY_P3T						38
>>>  
>>>  /* TA macros */
>>> @@ -480,6 +481,7 @@ enum ta_pmf_error_type {
>>>  };
>>>  
>>>  struct pmf_action_table {
>>> +	unsigned long display_brightness;
>>>  	enum system_state system_state;
>>>  	unsigned long spl; /* in mW */
>>>  	unsigned long sppt; /* in mW */
>>> diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c
>>> index 1608996654e8..eefffff83a4c 100644
>>> --- a/drivers/platform/x86/amd/pmf/tee-if.c
>>> +++ b/drivers/platform/x86/amd/pmf/tee-if.c
>>> @@ -79,10 +79,10 @@ static int amd_pmf_update_uevents(struct amd_pmf_dev *dev, u16 event)
>>>  	return 0;
>>>  }
>>>  
>>> -static void amd_pmf_apply_policies(struct amd_pmf_dev *dev, struct ta_pmf_enact_result *out)
>>> +static int amd_pmf_apply_policies(struct amd_pmf_dev *dev, struct ta_pmf_enact_result *out)
>>>  {
>>>  	u32 val, event = 0;
>>> -	int idx;
>>> +	int idx, ret;
>>>  
>>>  	for (idx = 0; idx < out->actions_count; idx++) {
>>>  		val = out->actions_list[idx].value;
>>> @@ -160,8 +160,23 @@ static void amd_pmf_apply_policies(struct amd_pmf_dev *dev, struct ta_pmf_enact_
>>>  				dev->prev_data->system_state = 0;
>>>  			}
>>>  			break;
>>> +
>>> +		case PMF_POLICY_DISPLAY_BRIGHTNESS:
>>> +			ret = amd_pmf_get_gfx_data(&dev->gfx_data);
>>> +			if (ret)
>>> +				return ret;
>>> +
>>> +			dev->prev_data->display_brightness = dev->gfx_data.brightness;
>>> +			if (dev->prev_data->display_brightness != val) {
>>> +				dev->gfx_data.brightness = val;
>>> +				amd_pmf_set_gfx_data(&dev->gfx_data);
>>> +				dev_dbg(dev->dev, "update DISPLAY_BRIGHTNESS : %d\n", val);
>>> +			}
>>> +			break;
>>>  		}
>>>  	}
>>> +
>>> +	return 0;
>>>  }
>>>  
>>>  static int amd_pmf_invoke_cmd_enact(struct amd_pmf_dev *dev)
>>> diff --git a/include/linux/amd-pmf-io.h b/include/linux/amd-pmf-io.h
>>> index a2d4af231362..ecae387ddaa6 100644
>>> --- a/include/linux/amd-pmf-io.h
>>> +++ b/include/linux/amd-pmf-io.h
>>> @@ -25,4 +25,5 @@ struct amd_gpu_pmf_data {
>>>  };
>>>  
>>>  int amd_pmf_get_gfx_data(struct amd_gpu_pmf_data *pmf);
>>> +int amd_pmf_set_gfx_data(struct amd_gpu_pmf_data *pmf);
>>>  #endif
>>
> 



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