drm/omap: Move DISPC runtime PM handling to omapdrm

The internal encoders (DSI, HDMI4, HDMI5 and VENC) runtime PM handlers
attempt to manage the runtime PM state of the connected DISPC, based on
the rationale that the DISPC providing data to the encoders requires
ensuring that the display is active whenever the encoders are active.

While the DISPC provides data to the encoders, it doesn't as such
constitute a resource that encoders require in order to be taken out
of suspend, contrary to for instance a functional clock or a power
supply. Encoders registers can be accessed without the DISPC being
active, and while the encoders will not output any video stream without
being fed by the DISPC, the DISPC PM state doesn't influence the
encoders PM state.

For this reason the DISPC PM state is better managed from the omapdrm
driver, in the CRTC enable and disable operations. This allows the
encoders PM state to be handled separately from the DISPC, and in
particular at times when the DISPC may not be available (for instance at
probe due to the DSS probe being deferred, or at remove time du to the
DISPC being already removed).

Fixes: edb715dffdee ("drm/omap: dss: dsi: Move initialization code from bind to probe")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181110111654.4387-5-laurent.pinchart@ideasonboard.com

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index 62928ec0e7db..caffc547ef97 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -350,11 +350,14 @@ static void omap_crtc_arm_event(struct drm_crtc *crtc)
 static void omap_crtc_atomic_enable(struct drm_crtc *crtc,
                                     struct drm_crtc_state *old_state)
 {
+        struct omap_drm_private *priv = crtc->dev->dev_private;
         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
         int ret;
 
         DBG("%s", omap_crtc->name);
 
+        priv->dispc_ops->runtime_get(priv->dispc);
+
         spin_lock_irq(&crtc->dev->event_lock);
         drm_crtc_vblank_on(crtc);
         ret = drm_crtc_vblank_get(crtc);
@@ -367,6 +370,7 @@ static void omap_crtc_atomic_enable(struct drm_crtc *crtc,
 static void omap_crtc_atomic_disable(struct drm_crtc *crtc,
                                      struct drm_crtc_state *old_state)
 {
+        struct omap_drm_private *priv = crtc->dev->dev_private;
         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
 
         DBG("%s", omap_crtc->name);
@@ -379,6 +383,8 @@ static void omap_crtc_atomic_disable(struct drm_crtc *crtc,
         spin_unlock_irq(&crtc->dev->event_lock);
 
         drm_crtc_vblank_off(crtc);
+
+        priv->dispc_ops->runtime_put(priv->dispc);
 }
 
 static enum drm_mode_status omap_crtc_mode_valid(struct drm_crtc *crtc,