[PATCH v2] drm/amdgpu/pm: Fix the power source flag error

[Ma, Jun]

Hi Lijo,

On 1/18/2024 5:24 PM, Lazar, Lijo wrote:
> On 1/18/2024 2:31 PM, Ma, Jun wrote:
>>
>>
>> On 1/18/2024 4:38 PM, Lazar, Lijo wrote:
>>> On 1/18/2024 12:57 PM, Ma Jun wrote:
>>>> The power source flag should be updated when
>>>> [1] System receives an interrupt indicating that the power source
>>>> has changed.
>>>> [2] System resumes from suspend or runtime suspend
>>>>
>>>> Signed-off-by: Ma Jun <Jun.Ma2 at amd.com>
>>>> ---
>>>>    drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c      | 13 +++----------
>>>>    drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c |  2 ++
>>>>    drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c |  2 ++
>>>>    3 files changed, 7 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
>>>> index c16703868e5c..a54663f2e2ab 100644
>>>> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
>>>> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
>>>> @@ -24,6 +24,7 @@
>>>>    
>>>>    #include <linux/firmware.h>
>>>>    #include <linux/pci.h>
>>>> +#include <linux/power_supply.h>
>>>>    #include <linux/reboot.h>
>>>>    
>>>>    #include "amdgpu.h"
>>>> @@ -817,16 +818,8 @@ static int smu_late_init(void *handle)
>>>>    	 * handle the switch automatically. Driver involvement
>>>>    	 * is unnecessary.
>>>>    	 */
>>>> -	if (!smu->dc_controlled_by_gpio) {
>>>> -		ret = smu_set_power_source(smu,
>>>> -					   adev->pm.ac_power ? SMU_POWER_SOURCE_AC :
>>>> -					   SMU_POWER_SOURCE_DC);
>>>> -		if (ret) {
>>>> -			dev_err(adev->dev, "Failed to switch to %s mode!\n",
>>>> -				adev->pm.ac_power ? "AC" : "DC");
>>>> -			return ret;
>>>> -		}
>>>> -	}
>>>> +	adev->pm.ac_power = power_supply_is_system_supplied() > 0;
>>>> +	smu_set_ac_dc(smu);
>>>
>>> In the older logic, driver initialization/resume fails if the message
>>> fails. This one doesn't care about the return value. Is there a reason
>>> to ignore and continue?
>>
>> I think printing an error message in smu_set_ac_dc() is enough,
>> and stopping the driver initialization/resume seems a bit excessive.
>>
> 
> FW not responding to a message usually means FW is not in a good state 
> which could later affect the system anyway. Since there are other FW 
> interactions after this probably ignoring this is fine.
> 
> BTW, what is the issue seen after resume when power source is not set 
> correctly? If that issue creates real problems, then it's worth 
> considering keeping the FW informed about the real power source, and 
> fail if it doesn't succeed.
> 
I didn't see any serious problems, the only problem is we may read incorrect
power related data values because of wrong ac_power value.

Regards,
Ma Jun
> Thanks,
> Lijo
> 
>> Regards,
>> Ma Jun
>>>
>>> Thanks,
>>> Lijo
>>>>    
>>>>    	if ((amdgpu_ip_version(adev, MP1_HWIP, 0) == IP_VERSION(13, 0, 1)) ||
>>>>    	    (amdgpu_ip_version(adev, MP1_HWIP, 0) == IP_VERSION(13, 0, 3)))
>>>> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
>>>> index 2e7f8d5cfc28..8047150fddd4 100644
>>>> --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
>>>> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
>>>> @@ -1442,10 +1442,12 @@ static int smu_v11_0_irq_process(struct amdgpu_device *adev,
>>>>    			case 0x3:
>>>>    				dev_dbg(adev->dev, "Switched to AC mode!\n");
>>>>    				schedule_work(&smu->interrupt_work);
>>>> +				adev->pm.ac_power = true;
>>>>    				break;
>>>>    			case 0x4:
>>>>    				dev_dbg(adev->dev, "Switched to DC mode!\n");
>>>>    				schedule_work(&smu->interrupt_work);
>>>> +				adev->pm.ac_power = false;
>>>>    				break;
>>>>    			case 0x7:
>>>>    				/*
>>>> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c
>>>> index 771a3d457c33..c486182ff275 100644
>>>> --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c
>>>> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c
>>>> @@ -1379,10 +1379,12 @@ static int smu_v13_0_irq_process(struct amdgpu_device *adev,
>>>>    			case 0x3:
>>>>    				dev_dbg(adev->dev, "Switched to AC mode!\n");
>>>>    				smu_v13_0_ack_ac_dc_interrupt(smu);
>>>> +				adev->pm.ac_power = true;
>>>>    				break;
>>>>    			case 0x4:
>>>>    				dev_dbg(adev->dev, "Switched to DC mode!\n");
>>>>    				smu_v13_0_ack_ac_dc_interrupt(smu);
>>>> +				adev->pm.ac_power = false;
>>>>    				break;
>>>>    			case 0x7:
>>>>    				/*
>>>
>