[Intel-gfx] [PATCH v3] drm/i915/psr: Force PSR probe only after full initialization

[Mun, Gwan-gyeong]

On Tue, 2020-02-18 at 12:39 -0800, José Roberto de Souza wrote:
> Commit 60c6a14b489b ("drm/i915/display: Force the state compute phase
> once to enable PSR") was forcing the state compute too earlier
> causing errors because not everything was initialized, so here
> moving to i915_driver_register() when everything is ready and driver
> is registering into the rest of the system.
> 
> Also fixing the place where it disarm the force probe as during the
> atomic check phase errors could happen like the ones due locking and
> it would cause PSR to never be enabled if that happens.
> Leaving the disarm to the atomic commit phase, intel_psr_enable() or
> intel_psr_update() will be called even if the current state do not
> allow PSR to be enabled.
> 
> v2: Check if intel_dp is null in intel_psr_force_mode_changed_set()
> v3: Check intel_dp before get dev_priv
> 
> Fixes: 60c6a14b489b ("drm/i915/display: Force the state compute phase
> once to enable PSR")
> Closes: https://gitlab.freedesktop.org/drm/intel/issues/1151
> Tested-by: Ross Zwisler <zwisler at google.com>
> Reported-by: Ross Zwisler <zwisler at google.com>
> Cc: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_psr.c | 22 ++++++++++++++++++++--
>  drivers/gpu/drm/i915/display/intel_psr.h |  1 +
>  drivers/gpu/drm/i915/i915_drv.c          |  3 +++
>  drivers/gpu/drm/i915/i915_drv.h          |  2 +-
>  4 files changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index b4942b6445ae..2a0f7354fba5 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -936,6 +936,8 @@ void intel_psr_enable(struct intel_dp *intel_dp,
>  {
>  	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
>  
> +	intel_psr_force_mode_changed_set(intel_dp, false);
> +
Hi,
intel_psr_enable() and intel_psr_update already have checking routine
for CAN_PSR and has_psr.
therefore we don't need to check twice here.
And if there are no issues that moving "disarming force_mode_changed"
to intel_psr_compute_config(), 
can we move them to intel_psr_compute_config()?

>  	if (!crtc_state->has_psr)
>  		return;
>  
> @@ -1096,6 +1098,8 @@ void intel_psr_update(struct intel_dp
> *intel_dp,
>  	struct i915_psr *psr = &dev_priv->psr;
>  	bool enable, psr2_enable;
>  
> +	intel_psr_force_mode_changed_set(intel_dp, false);
> +
>  	if (!CAN_PSR(dev_priv) || READ_ONCE(psr->dp) != intel_dp)
>  		return;
>  
> @@ -1629,7 +1633,7 @@ void intel_psr_atomic_check(struct
> drm_connector *connector,
>  	struct drm_crtc_state *crtc_state;
>  
>  	if (!CAN_PSR(dev_priv) || !new_state->crtc ||
> -	    dev_priv->psr.initially_probed)
> +	    !dev_priv->psr.force_mode_changed)
>  		return;
>  
>  	intel_connector = to_intel_connector(connector);
> @@ -1640,5 +1644,19 @@ void intel_psr_atomic_check(struct
> drm_connector *connector,
>  	crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
>  						   new_state->crtc);
>  	crtc_state->mode_changed = true;
> -	dev_priv->psr.initially_probed = true;
> +}
> +
> +void intel_psr_force_mode_changed_set(struct intel_dp *intel_dp,
> bool set)
IMHO, it would be better intel_psr_set_force_mode_changed() as a
function name.
> +{
> +	struct drm_i915_private *dev_priv;
> +
> +	if (!intel_dp)
> +		return;
> +
> +	dev_priv = dp_to_i915(intel_dp);
> +	if (!CAN_PSR(dev_priv) || !intel_dp_is_edp(intel_dp) ||
> +	    intel_dp != dev_priv->psr.dp)
> +		return;
> +
> +	dev_priv->psr.force_mode_changed = set;
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.h
> b/drivers/gpu/drm/i915/display/intel_psr.h
> index c58a1d438808..27a70468e2b9 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.h
> +++ b/drivers/gpu/drm/i915/display/intel_psr.h
> @@ -40,5 +40,6 @@ bool intel_psr_enabled(struct intel_dp *intel_dp);
>  void intel_psr_atomic_check(struct drm_connector *connector,
>  			    struct drm_connector_state *old_state,
>  			    struct drm_connector_state *new_state);
> +void intel_psr_force_mode_changed_set(struct intel_dp *intel_dp,
> bool set);
>  
>  #endif /* __INTEL_PSR_H__ */
> diff --git a/drivers/gpu/drm/i915/i915_drv.c
> b/drivers/gpu/drm/i915/i915_drv.c
> index f7a1c33697b7..83791c197611 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -58,6 +58,7 @@
>  #include "display/intel_hotplug.h"
>  #include "display/intel_overlay.h"
>  #include "display/intel_pipe_crc.h"
> +#include "display/intel_psr.h"
>  #include "display/intel_sprite.h"
>  #include "display/intel_vga.h"
>  
> @@ -1256,6 +1257,8 @@ static void i915_driver_register(struct
> drm_i915_private *dev_priv)
>  
>  	intel_audio_init(dev_priv);
>  
> +	intel_psr_force_mode_changed_set(dev_priv->psr.dp, true);
> +
>  	/*
>  	 * Some ports require correctly set-up hpd registers for
> detection to
>  	 * work properly (leading to ghost connected connector status),
> e.g. VGA
> diff --git a/drivers/gpu/drm/i915/i915_drv.h
> b/drivers/gpu/drm/i915/i915_drv.h
> index 3330b538d379..a546655072bd 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -505,7 +505,7 @@ struct i915_psr {
>  	bool dc3co_enabled;
>  	u32 dc3co_exit_delay;
>  	struct delayed_work dc3co_work;
> -	bool initially_probed;
> +	bool force_mode_changed;
>  };
>  
>  #define QUIRK_LVDS_SSC_DISABLE (1<<1)