Re: [PATCH v5 02/10] drm/hdcp: Avoid changing crtc state in hdcp atomic check

On Mon, Apr 11, 2022 at 08:47:31PM +0000, Sean Paul wrote:

From: Sean Paul seanpaul@chromium.org

Instead of forcing a modeset in the hdcp atomic check, simply return true if the content protection value is changing and let the driver decide whether a modeset is required or not.

Acked-by: Jani Nikula jani.nikula@intel.com Signed-off-by: Sean Paul seanpaul@chromium.org Link: https://patchwork.freedesktop.org/patch/msgid/20210913175747.47456-3-sean@po... #v1 Link: https://patchwork.freedesktop.org/patch/msgid/20210915203834.1439-3-sean@poo... #v2 Link: https://patchwork.freedesktop.org/patch/msgid/20211001151145.55916-3-sean@po... #v3 Link: https://patchwork.freedesktop.org/patch/msgid/20211105030434.2828845-3-sean@... #v4

Changes in v2: -None Changes in v3: -None Changes in v4: -None Changes in v5:

-None

drivers/gpu/drm/drm_hdcp.c | 33 +++++++++++++++------ drivers/gpu/drm/i915/display/intel_atomic.c | 5 ++-- include/drm/drm_hdcp.h | 2 +- 3 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c index 522326b03e66..dd8fa91c51d6 100644 --- a/drivers/gpu/drm/drm_hdcp.c +++ b/drivers/gpu/drm/drm_hdcp.c @@ -430,11 +430,14 @@ EXPORT_SYMBOL(drm_hdcp_update_content_protection);

• @connector: drm_connector on which content protection state needs an update
• This function can be used by display drivers to perform an atomic check on the

• • hdcp state elements. If hdcp state has changed, this function will set
• • mode_changed on the crtc driving the connector so it can update its hardware
• • to match the hdcp state.

• • hdcp state elements. If hdcp state has changed in a manner which requires the
• • driver to enable or disable content protection, this function will return
• • true.
• • Returns:
• • true if the driver must enable/disable hdcp, false otherwise
  */

-void drm_hdcp_atomic_check(struct drm_connector *connector, +bool drm_hdcp_atomic_check(struct drm_connector *connector, struct drm_atomic_state *state) { struct drm_connector_state *new_conn_state, *old_conn_state; @@ -452,10 +455,12 @@ void drm_hdcp_atomic_check(struct drm_connector *connector, * If the connector is being disabled with CP enabled, mark it * desired so it's re-enabled when the connector is brought back */

• if (old_hdcp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
  

• if (old_hdcp == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
  new_conn_state->content_protection =
  	DRM_MODE_CONTENT_PROTECTION_DESIRED;
  

• return;
  

• 	return true;
  

• }
  

• return false;
  

  }

  new_crtc_state = drm_atomic_get_new_crtc_state(state,

@@ -467,9 +472,19 @@ void drm_hdcp_atomic_check(struct drm_connector *connector, */ if (drm_atomic_crtc_needs_modeset(new_crtc_state) && (old_hdcp == DRM_MODE_CONTENT_PROTECTION_ENABLED &&

•     new_hdcp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED))
  

•     new_hdcp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED)) {
  

  new_conn_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;

• return true;
  

• }
• /*

• * Coming back from disable or changing CRTC with DESIRED state requires
  

• * that the driver try CP enable.
  

• */
  

• if (new_hdcp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&

•    new_conn_state->crtc != old_conn_state->crtc)
  

• return true;
  

I'm with the feeling that this chunk should deserve a separated patch. But the reason looks correct so anyway

Reviewed-by: Rodrigo Vivi rodrigo.vivi@intel.com

/* * Nothing to do if content type is unchanged and one of: @@ -484,9 +499,9 @@ void drm_hdcp_atomic_check(struct drm_connector *connector, new_hdcp == DRM_MODE_CONTENT_PROTECTION_DESIRED)) { if (old_conn_state->hdcp_content_type == new_conn_state->hdcp_content_type)

• 	return;
  

• 	return false;
  

  }

• new_crtc_state->mode_changed = true;

• return true;

} EXPORT_SYMBOL(drm_hdcp_atomic_check); diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c index b301a4d1017e..6d24b3450399 100644 --- a/drivers/gpu/drm/i915/display/intel_atomic.c +++ b/drivers/gpu/drm/i915/display/intel_atomic.c @@ -124,8 +124,6 @@ int intel_digital_connector_atomic_check(struct drm_connector *conn, to_intel_digital_connector_state(old_state); struct drm_crtc_state *crtc_state;

• drm_hdcp_atomic_check(conn, state);
• if (!new_state->crtc) return 0;

@@ -142,7 +140,8 @@ int intel_digital_connector_atomic_check(struct drm_connector *conn, new_conn_state->base.content_type != old_conn_state->base.content_type || new_conn_state->base.scaling_mode != old_conn_state->base.scaling_mode || new_conn_state->base.privacy_screen_sw_state != old_conn_state->base.privacy_screen_sw_state ||

•    !drm_connector_atomic_hdr_metadata_equal(old_state, new_state))
  

•    !drm_connector_atomic_hdr_metadata_equal(old_state, new_state) ||
  

•    drm_hdcp_atomic_check(conn, state))
  

  crtc_state->mode_changed = true;

  return 0;

diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index d49977a042e1..e6e3d16bc7d3 100644 --- a/include/drm/drm_hdcp.h +++ b/include/drm/drm_hdcp.h @@ -301,7 +301,7 @@ int drm_connector_attach_content_protection_property( struct drm_connector *connector, bool hdcp_content_type); void drm_hdcp_update_content_protection(struct drm_connector *connector, u64 val); -void drm_hdcp_atomic_check(struct drm_connector *connector, +bool drm_hdcp_atomic_check(struct drm_connector *connector, struct drm_atomic_state *state);

/* Content Type classification for HDCP2.2 vs others */

Sean Paul, Software Engineer, Google / Chromium OS