Re: [PATCH v3 6/8] drm/i915: Disable power management for i915 driver in VM

Tvrtko Ursulin
2014-12-12T13:27:49Z

On 11/13/2014 12:02 PM, Yu Zhang wrote:
> With Intel GVT-g, GPU power management is controlled by
> host driver, so there is no need to provide virtualized
> GPU PM support. In the future it might be useful to gather
> VM input for freq boost, but now let's disable it simply.
>
> v2:
> take Chris' comments:
> - do not special case this to gen6+
>
> Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>
> Signed-off-by: Jike Song <jike.song@intel.com>
> ---
> drivers/gpu/drm/i915/intel_pm.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 3bc5d93..3722bd4 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -5314,6 +5314,10 @@ void intel_enable_gt_powersave(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
>
> + /* Powersaving is controlled by the host when inside a VM */
> + if (intel_vgpu_active(dev))
> + return;
> +
> if (IS_IRONLAKE_M(dev)) {
> mutex_lock(&dev->struct_mutex);
> ironlake_enable_drps(dev);
>

I was looking for potential call sites of this which come earlier than
i915_check_vgpu. Didn't find any but found RPS (intel_pm_setup) - what's
with that - should it be disabled as well?

Otherwise,

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>