[PATCH v2 4/4] drm/amd/pm: Add sysfs attribute to get pm log

[Christian König]

Am 06.10.23 um 07:21 schrieb Lijo Lazar:
> Add sysfs attribute to read power management log. A snapshot is
> captured to the buffer when the attribute is read.
>
> Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
> ---
>
> v2: Pass PAGE_SIZE as the max size of input buffer
>
>   drivers/gpu/drm/amd/pm/amdgpu_pm.c | 40 ++++++++++++++++++++++++++++++
>   1 file changed, 40 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> index 4c65a2fac028..5a1d21c52672 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> @@ -1794,6 +1794,44 @@ static ssize_t amdgpu_set_apu_thermal_cap(struct device *dev,
>   	return count;
>   }
>   
> +static int amdgpu_pmlog_attr_update(struct amdgpu_device *adev,
> +				    struct amdgpu_device_attr *attr,
> +				    uint32_t mask,
> +				    enum amdgpu_device_attr_states *states)
> +{
> +	if (amdgpu_dpm_get_pm_log(adev, NULL, 0) == -EOPNOTSUPP)
> +		*states = ATTR_STATE_UNSUPPORTED;
> +
> +	return 0;
> +}
> +
> +static ssize_t amdgpu_get_pmlog(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);
> +	ssize_t size = 0;
> +	int ret;
> +
> +	if (amdgpu_in_reset(adev))
> +		return -EPERM;

Please stop using amdgpu_in_reset() for stuff like that altogether.

When this is reset critical it should grab the reset rw semaphore. If it 
isn't than that check isn't necessary.

Regards,
Christian.

> +	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;
> +	}
> +
> +	size = amdgpu_dpm_get_pm_log(adev, buf, PAGE_SIZE);
> +
> +	pm_runtime_mark_last_busy(ddev->dev);
> +	pm_runtime_put_autosuspend(ddev->dev);
> +
> +	return size;
> +}
> +
>   /**
>    * DOC: gpu_metrics
>    *
> @@ -2091,6 +2129,8 @@ static struct amdgpu_device_attr amdgpu_device_attrs[] = {
>   	AMDGPU_DEVICE_ATTR_RW(smartshift_bias,				ATTR_FLAG_BASIC,
>   			      .attr_update = ss_bias_attr_update),
>   	AMDGPU_DEVICE_ATTR_RW(xgmi_plpd_policy,				ATTR_FLAG_BASIC),
> +	AMDGPU_DEVICE_ATTR_RO(pmlog,					ATTR_FLAG_BASIC,
> +			      .attr_update = amdgpu_pmlog_attr_update),
>   };
>   
>   static int default_attr_update(struct amdgpu_device *adev, struct amdgpu_device_attr *attr,