Chris Wilson <ch...@chris-wilson.co.uk> writes:
> We currently call intel_mark_idle() too often, as we do so as a
> side-effect of processing the request queue. However, we the calls to
> intel_mark_idle() are expected to be paired with a call to
> intel_mark_busy() (or else we try to idle the hardware by accessing
> registers that are already disabled). Make the idle/busy tracking
> explicit to prevent the multiple calls.
>
> Reported-by: Paulo Zanoni <paulo.r.zan...@intel.com>
> Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
> Cc: Paulo Zanoni <paulo.r.zan...@intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 8 ++++++++
> drivers/gpu/drm/i915/i915_gem.c | 4 +---
> drivers/gpu/drm/i915/intel_display.c | 11 +++++++++++
> drivers/gpu/drm/i915/intel_drv.h | 2 +-
> 4 files changed, 21 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 00222cc..8441c8a 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1134,6 +1134,14 @@ struct i915_gem_mm {
> */
> bool interruptible;
>
> + /**
> + * Is the GPU currently considered idle, or busy executing userspace
> + * requests? Whilst idle, we attempt to power down the hardware and
> + * display clocks. In order to reduce the effect on performance, there
> + * is a slight delay before we do so.
> + */
> + bool busy;
> +
> /** Bit 6 swizzling required for X tiling */
> uint32_t bit_6_swizzle_x;
> /** Bit 6 swizzling required for Y tiling */
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 9a40ef5..4525dd7 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2315,7 +2315,6 @@ int __i915_add_request(struct intel_ring_buffer *ring,
> i915_gem_context_reference(request->ctx);
>
> request->emitted_jiffies = jiffies;
> - was_empty = list_empty(&ring->request_list);
> list_add_tail(&request->list, &ring->request_list);
> request->file_priv = NULL;
>
> @@ -2336,12 +2335,11 @@ int __i915_add_request(struct intel_ring_buffer *ring,
> if (!dev_priv->ums.mm_suspended) {
> i915_queue_hangcheck(ring->dev);
>
> - if (was_empty) {
> + if (intel_mark_busy(dev_priv->dev)) {
> cancel_delayed_work_sync(&dev_priv->mm.idle_work);
> queue_delayed_work(dev_priv->wq,
> &dev_priv->mm.retire_work,
> round_jiffies_up_relative(HZ));
> - intel_mark_busy(dev_priv->dev);
> }
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c
> index e127b23..bfd6396 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -8220,8 +8220,14 @@ void intel_mark_busy(
bool intel_mark_busy(struct drm_device *dev)
-Mika
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
>
> + if (dev_priv->mm.busy)
> + return false;
> +
> hsw_package_c8_gpu_busy(dev_priv);
> i915_update_gfx_val(dev_priv);
> + dev_priv->mm.busy = true;
> +
> + return true;
> }
>
> void intel_mark_idle(struct drm_device *dev)
> @@ -8229,6 +8235,11 @@ void intel_mark_idle(struct drm_device *dev)
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct drm_crtc *crtc;
>
> + if (!dev_priv->mm.busy)
> + return;
> +
> + dev_priv->mm.busy = false;
> +
> hsw_package_c8_gpu_idle(dev_priv);
>
> if (!i915.powersave)
> diff --git a/drivers/gpu/drm/i915/intel_drv.h
> b/drivers/gpu/drm/i915/intel_drv.h
> index e5e1a5c..4c329e0 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -656,7 +656,7 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
> const char *intel_output_name(int output);
> bool intel_has_pending_fb_unpin(struct drm_device *dev);
> int intel_pch_rawclk(struct drm_device *dev);
> -void intel_mark_busy(struct drm_device *dev);
> +bool intel_mark_busy(struct drm_device *dev);
> void intel_mark_fb_busy(struct drm_i915_gem_object *obj,
> struct intel_ring_buffer *ring);
> void intel_mark_idle(struct drm_device *dev);
> --
> 1.7.9.5
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
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