Re: [PATCH] drm/radeon/pm: handle powered down GPUs properly in sysfs/debugfs

["Christian König" <deathsimple@vodafone.de>]

Am 21.02.2014 16:50, schrieb Alex Deucher:
> When we power down the dGPU on a PX system, bail if the
> user tried to adjust the power state or check the temperature.
> The GPU is powered down, so it doesn't make sense to actually
> do anything.  We could power up the dGPU to complete the
> operation, but it would just be undone again as soon as it was
> completed as the card would be powered down again.  Return 0
> for temperature and return -EINVAL for other interfaces.
>
> bug:
> https://bugzilla.kernel.org/show_bug.cgi?id=70651
>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> Cc: stable@vger.kernel.org

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/radeon/radeon_pm.c | 29 ++++++++++++++++++++++++++---
>   1 file changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
> index 8e8153e..6f20bb0 100644
> --- a/drivers/gpu/drm/radeon/radeon_pm.c
> +++ b/drivers/gpu/drm/radeon/radeon_pm.c
> @@ -67,6 +67,11 @@ int radeon_pm_get_type_index(struct radeon_device *rdev,
>   
>   void radeon_pm_acpi_event_handler(struct radeon_device *rdev)
>   {
> +	struct drm_device *ddev = rdev->ddev;
> +
> +	if (ddev->switch_power_state == DRM_SWITCH_POWER_OFF)
> +		return;
> +
>   	if ((rdev->pm.pm_method == PM_METHOD_DPM) && rdev->pm.dpm_enabled) {
>   		mutex_lock(&rdev->pm.mutex);
>   		if (power_supply_is_system_supplied() > 0)
> @@ -361,6 +366,9 @@ static ssize_t radeon_set_pm_profile(struct device *dev,
>   	struct drm_device *ddev = dev_get_drvdata(dev);
>   	struct radeon_device *rdev = ddev->dev_private;
>   
> +	if (ddev->switch_power_state == DRM_SWITCH_POWER_OFF)
> +		return -EINVAL;
> +
>   	mutex_lock(&rdev->pm.mutex);
>   	if (rdev->pm.pm_method == PM_METHOD_PROFILE) {
>   		if (strncmp("default", buf, strlen("default")) == 0)
> @@ -410,7 +418,8 @@ static ssize_t radeon_set_pm_method(struct device *dev,
>   	struct radeon_device *rdev = ddev->dev_private;
>   
>   	/* we don't support the legacy modes with dpm */
> -	if (rdev->pm.pm_method == PM_METHOD_DPM) {
> +	if ((rdev->pm.pm_method == PM_METHOD_DPM) ||
> +	    (ddev->switch_power_state == DRM_SWITCH_POWER_OFF)) {
>   		count = -EINVAL;
>   		goto fail;
>   	}
> @@ -459,6 +468,11 @@ static ssize_t radeon_set_dpm_state(struct device *dev,
>   	struct drm_device *ddev = dev_get_drvdata(dev);
>   	struct radeon_device *rdev = ddev->dev_private;
>   
> +	if (ddev->switch_power_state == DRM_SWITCH_POWER_OFF) {
> +		count = -EINVAL;
> +		goto fail;
> +	}
> +
>   	mutex_lock(&rdev->pm.mutex);
>   	if (strncmp("battery", buf, strlen("battery")) == 0)
>   		rdev->pm.dpm.user_state = POWER_STATE_TYPE_BATTERY;
> @@ -500,6 +514,9 @@ static ssize_t radeon_set_dpm_forced_performance_level(struct device *dev,
>   	enum radeon_dpm_forced_level level;
>   	int ret = 0;
>   
> +	if (ddev->switch_power_state == DRM_SWITCH_POWER_OFF)
> +		return -EINVAL;
> +
>   	mutex_lock(&rdev->pm.mutex);
>   	if (strncmp("low", buf, strlen("low")) == 0) {
>   		level = RADEON_DPM_FORCED_LEVEL_LOW;
> @@ -538,9 +555,13 @@ static ssize_t radeon_hwmon_show_temp(struct device *dev,
>   				      char *buf)
>   {
>   	struct radeon_device *rdev = dev_get_drvdata(dev);
> +	struct drm_device *ddev = rdev->ddev;
>   	int temp;
>   
> -	if (rdev->asic->pm.get_temperature)
> +	/* return 0 if PX card is off */
> +	if (ddev->switch_power_state == DRM_SWITCH_POWER_OFF)
> +		temp = 0;
> +	else if (rdev->asic->pm.get_temperature)
>   		temp = radeon_get_temperature(rdev);
>   	else
>   		temp = 0;
> @@ -1579,7 +1600,9 @@ static int radeon_debugfs_pm_info(struct seq_file *m, void *data)
>   	struct drm_device *dev = node->minor->dev;
>   	struct radeon_device *rdev = dev->dev_private;
>   
> -	if (rdev->pm.dpm_enabled) {
> +	if (dev->switch_power_state == DRM_SWITCH_POWER_OFF) {
> +		seq_printf(m, "Chip powered off\n");
> +	} else if (rdev->pm.dpm_enabled) {
>   		mutex_lock(&rdev->pm.mutex);
>   		if (rdev->asic->dpm.debugfs_print_current_performance_level)
>   			radeon_dpm_debugfs_print_current_performance_level(rdev, m);