[Intel-gfx] [PATCH] drm/i915/psr: Kill delays when activating psr back.
Dhinakaran Pandiyan
dhinakaran.pandiyan at intel.com
Wed Jun 13 23:49:05 UTC 2018
On Wed, 2018-06-13 at 12:26 -0700, Rodrigo Vivi wrote:
> The immediate enabling was actually not an issue for the
> HW perspective for core platforms that have HW tracking.
> HW will wait few identical idle frames before transitioning
> to actual psr active anyways.
>
> Now that we removed VLV/CHV out of the picture completely
> we can safely remove any delays.
>
> Note that this patch also remove the delayed activation
> on HSW and BDW introduced by commit 'd0ac896a477d
> ("drm/i915: Delay first PSR activation.")'. This was
> introduced to fix a blank screen on VLV/CHV and also
> masked some frozen screens on other core platforms.
> Probably the same that we are now properly hunting and fixing.
>
> v2:(DK): Remove unnecessary WARN_ONs and make some other
> VLV | CHV more readable.
> v3: Do it regardless the timer rework.
> v4: (DK/CI): Add VLV || CHV check on cancel work at psr_disable.
> v5: Kill remaining items and fully rework activation functions.
> v6: Rebase on top of VLV/CHV clean-up and keep the reactivation
> on a regular non-delayed work to avoid extra delays on exit
> calls and allow us to add few more safety checks before
> real activation.
We have to implement this bspec step in the disable sequence now that
you are removing the delay -
"Wait for SRD_STATUS to show SRD is Idle. This will take up to one full
frame time (1/refresh rate), plus SRD exit training time (max of 6ms),
plus SRD aux channel handshake (max of 1.5ms)."
Otherwise, we can end up re-enabling right after a disable in
psr_exit()
>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 2 --
> drivers/gpu/drm/i915/i915_drv.h | 2 +-
> drivers/gpu/drm/i915/intel_psr.c | 29 +++++++------------------
> ----
> 3 files changed, 8 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> b/drivers/gpu/drm/i915/i915_debugfs.c
> index 769ab9745834..948b973af067 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2660,8 +2660,6 @@ static int i915_edp_psr_status(struct seq_file
> *m, void *data)
> seq_printf(m, "Enabled: %s\n", yesno((bool)dev_priv-
> >psr.enabled));
> seq_printf(m, "Busy frontbuffer bits: 0x%03x\n",
> dev_priv->psr.busy_frontbuffer_bits);
> - seq_printf(m, "Re-enable work scheduled: %s\n",
> - yesno(work_busy(&dev_priv->psr.work.work)));
>
> if (dev_priv->psr.psr2_enabled)
> enabled = I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE;
> diff --git a/drivers/gpu/drm/i915/i915_drv.h
> b/drivers/gpu/drm/i915/i915_drv.h
> index be8c2f0823c4..19defe73b156 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -613,7 +613,7 @@ struct i915_psr {
> bool sink_support;
> struct intel_dp *enabled;
> bool active;
> - struct delayed_work work;
> + struct work_struct work;
> unsigned busy_frontbuffer_bits;
> bool sink_psr2_support;
> bool link_standby;
> diff --git a/drivers/gpu/drm/i915/intel_psr.c
> b/drivers/gpu/drm/i915/intel_psr.c
> index 71dfe541740f..ef0f4741a95d 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -671,21 +671,7 @@ void intel_psr_enable(struct intel_dp *intel_dp,
> dev_priv->psr.enable_source(intel_dp, crtc_state);
> dev_priv->psr.enabled = intel_dp;
>
> - if (INTEL_GEN(dev_priv) >= 9) {
> - intel_psr_activate(intel_dp);
> - } else {
> - /*
> - * FIXME: Activation should happen immediately since
> this
> - * function is just called after pipe is fully
> trained and
> - * enabled.
> - * However on some platforms we face issues when
> first
> - * activation follows a modeset so quickly.
> - * - On HSW/BDW we get a recoverable frozen
> screen until
> - * next exit-activate sequence.
> - */
> - schedule_delayed_work(&dev_priv->psr.work,
> - msecs_to_jiffies(intel_dp-
> >panel_power_cycle_delay * 5));
> - }
> + intel_psr_activate(intel_dp);
>
> unlock:
> mutex_unlock(&dev_priv->psr.lock);
> @@ -768,8 +754,6 @@ void intel_psr_disable(struct intel_dp *intel_dp,
>
> dev_priv->psr.enabled = NULL;
> mutex_unlock(&dev_priv->psr.lock);
> -
> - cancel_delayed_work_sync(&dev_priv->psr.work);
> }
>
> static bool psr_wait_for_idle(struct drm_i915_private *dev_priv)
> @@ -805,10 +789,13 @@ static bool psr_wait_for_idle(struct
> drm_i915_private *dev_priv)
> static void intel_psr_work(struct work_struct *work)
> {
> struct drm_i915_private *dev_priv =
> - container_of(work, typeof(*dev_priv),
> psr.work.work);
> + container_of(work, typeof(*dev_priv), psr.work);
>
> mutex_lock(&dev_priv->psr.lock);
>
> + if (!dev_priv->psr.enabled)
> + goto unlock;
> +
I thought flush_work() was missing in psr_disable(), but this check
should take care of not enabling PSR after psr_disable()
> /*
> * We have to make sure PSR is ready for re-enable
> * otherwise it keeps disabled until next full
> enable/disable cycle.
> @@ -949,9 +936,7 @@ void intel_psr_flush(struct drm_i915_private
> *dev_priv,
> }
>
> if (!dev_priv->psr.active && !dev_priv-
> >psr.busy_frontbuffer_bits)
> - if (!work_busy(&dev_priv->psr.work.work))
> - schedule_delayed_work(&dev_priv->psr.work,
> - msecs_to_jiffies(100))
> ;
> + schedule_work(&dev_priv->psr.work);
> mutex_unlock(&dev_priv->psr.lock);
> }
>
> @@ -998,7 +983,7 @@ void intel_psr_init(struct drm_i915_private
> *dev_priv)
> dev_priv->psr.link_standby = false;
> }
>
> - INIT_DELAYED_WORK(&dev_priv->psr.work, intel_psr_work);
> + INIT_WORK(&dev_priv->psr.work, intel_psr_work);
> mutex_init(&dev_priv->psr.lock);
>
> dev_priv->psr.enable_source = hsw_psr_enable_source;
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