[PATCH 2/2] drm/amdgpu: allow APU to send power gate message when dpm is disabled

[Lazar, Lijo]

On 12/3/2021 12:24 PM, Lang Yu wrote:
> The general hw fini sequence is SMU-> ... ->SDMA-> ...
> We need to send power gate message to power off SDMA(in SDMA hw_fini())
> afer dpm is disabled(in SMU hw_fini()). Allow that for APU.

This message is not right. In APUs there is no message provided by FW to 
enable/disable DPM, it is done in BIOS. Rephrase to something like after 
smu hw_fini is completed.

> 
> Signed-off-by: Lang Yu <lang.yu at amd.com>
> ---
>   drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index 2d718c30c8eb..285a237f3605 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -277,7 +277,7 @@ static int smu_dpm_set_power_gate(void *handle,
>   	struct smu_context *smu = handle;
>   	int ret = 0;
>   
> -	if (!smu->pm_enabled || !smu->adev->pm.dpm_enabled) {
> +	if (!smu->pm_enabled || (!smu->is_apu && !smu->adev->pm.dpm_enabled)) {


This check was there before also, only the WARN is added. That means it 
was skipping sending messages in APUs also and so far this was working 
fine (until this gets noticed because of the warning).

Now this would try to send the message to APU without any check. That 
doesn't look good. Ideal way should be to fix the sequence. Otherwise, 
suggest to do something like below as the last step of smu hw cleanup 
rather than sending the message blindly.

	if (smu->is_apu)
		smu->pm.dpm_enabled = smu_is_dpm_running(smu);

Thanks,
Lijo

>   		dev_WARN(smu->adev->dev,
>   			 "SMU uninitialized but power %s requested for %u!\n",
>   			 gate ? "gate" : "ungate", block_type);
>