[PATCH/RFC,384/390] drm/rcar-du: Reorganize CRTC start/stop and power management code

Commit Message

Simon Horman March 29, 2013, 2:45 a.m. UTC

From: Laurent Pinchart <[e-mail]>

The DU is acquired in the CRTC start handler and released in its stop
handler. This prevents accessing the hardware from encoder code.

Reorganize the CRTC code to acquire the DU at mode set prepare time and
DPMS on time, and release it when the CRTC is disabled.

Signed-off-by: Laurent Pinchart <[e-mail]>
(cherry picked from commit c8f79e4087c2df2515e541d2a03d1fa92bc96d33)

Signed-off-by: Simon Horman <[e-mail]>
---
 drivers/gpu/drm/rcar-du/rcar_du_crtc.c |   53 ++++++++++++++++++++++++++------
 1 file changed, 43 insertions(+), 10 deletions(-)

Patch

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 0e5eab1..98c54ff 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -232,8 +232,6 @@  static void rcar_du_crtc_start(struct rcar_du_crtc *rcrtc)
 	if (WARN_ON(rcrtc->plane->format == NULL))
 		return;
 
-	rcar_du_get(rcdu);
-
 	/* Set display off and background to black */
 	rcar_du_crtc_write(rcrtc, DOOR, DOOR_RGB(0, 0, 0));
 	rcar_du_crtc_write(rcrtc, BPOR, BPOR_RGB(0, 0, 0));
@@ -290,21 +288,25 @@  static void rcar_du_crtc_stop(struct rcar_du_crtc *rcrtc)
 
 	rcar_du_start_stop(rcdu, false);
 
-	rcar_du_put(rcdu);
-
 	rcrtc->started = false;
 }
 
 void rcar_du_crtc_suspend(struct rcar_du_crtc *rcrtc)
 {
+	struct rcar_du_device *rcdu = rcrtc->crtc.dev->dev_private;
+
 	rcar_du_crtc_stop(rcrtc);
+	rcar_du_put(rcdu);
 }
 
 void rcar_du_crtc_resume(struct rcar_du_crtc *rcrtc)
 {
+	struct rcar_du_device *rcdu = rcrtc->crtc.dev->dev_private;
+
 	if (rcrtc->dpms != DRM_MODE_DPMS_ON)
 		return;
 
+	rcar_du_get(rcdu);
 	rcar_du_crtc_start(rcrtc);
 }
 
@@ -318,15 +320,19 @@  static void rcar_du_crtc_update_base(struct rcar_du_crtc *rcrtc)
 
 static void rcar_du_crtc_dpms(struct drm_crtc *crtc, int mode)
 {
+	struct rcar_du_device *rcdu = crtc->dev->dev_private;
 	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
 
 	if (rcrtc->dpms == mode)
 		return;
 
-	if (mode == DRM_MODE_DPMS_ON)
+	if (mode == DRM_MODE_DPMS_ON) {
+		rcar_du_get(rcdu);
 		rcar_du_crtc_start(rcrtc);
-	else
+	} else {
 		rcar_du_crtc_stop(rcrtc);
+		rcar_du_put(rcdu);
+	}
 
 	rcrtc->dpms = mode;
 }
@@ -341,10 +347,21 @@  static bool rcar_du_crtc_mode_fixup(struct drm_crtc *crtc,
 
 static void rcar_du_crtc_mode_prepare(struct drm_crtc *crtc)
 {
+	struct rcar_du_device *rcdu = crtc->dev->dev_private;
 	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
 
-	rcar_du_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
+	/* We need to access the hardware during mode set, acquire a reference
+	 * to the DU.
+	 */
+	rcar_du_get(rcdu);
+
+	/* Stop the CRTC and release the plane. Force the DPMS mode to off as a
+	 * result.
+	 */
+	rcar_du_crtc_stop(rcrtc);
 	rcar_du_plane_release(rcrtc->plane);
+
+	rcrtc->dpms = DRM_MODE_DPMS_OFF;
 }
 
 static int rcar_du_crtc_mode_set(struct drm_crtc *crtc,
@@ -362,12 +379,13 @@  static int rcar_du_crtc_mode_set(struct drm_crtc *crtc,
 	if (format == NULL) {
 		dev_dbg(rcdu->dev, "mode_set: unsupported format %08x\n",
 			crtc->fb->pixel_format);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto error;
 	}
 
 	ret = rcar_du_plane_reserve(rcrtc->plane, format);
 	if (ret < 0)
-		return ret;
+		goto error;
 
 	rcrtc->plane->format = format;
 	rcrtc->plane->pitch = crtc->fb->pitches[0];
@@ -380,11 +398,26 @@  static int rcar_du_crtc_mode_set(struct drm_crtc *crtc,
 	rcar_du_plane_compute_base(rcrtc->plane, crtc->fb);
 
 	return 0;
+
+error:
+	/* There's no rollback/abort operation to clean up in case of error. We
+	 * thus need to release the reference to the DU acquired in prepare()
+	 * here.
+	 */
+	rcar_du_put(rcdu);
+	return ret;
 }
 
 static void rcar_du_crtc_mode_commit(struct drm_crtc *crtc)
 {
-	rcar_du_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
+	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
+
+	/* We're done, restart the CRTC and set the DPMS mode to on. The
+	 * reference to the DU acquired at prepare() time will thus be released
+	 * by the DPMS handler (possibly called by the disable() handler).
+	 */
+	rcar_du_crtc_start(rcrtc);
+	rcrtc->dpms = DRM_MODE_DPMS_ON;
 }
 
 static int rcar_du_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,