nouveau: add runtime PM support (v0.9)

This hooks nouveau up to the runtime PM system to enable
dynamic power management for secondary GPUs in switchable
and optimus laptops.

a) rewrite suspend/resume printks to hide them during dynamic s/r
to avoid cluttering logs
b) add runtime pm suspend to irq handler, crtc display, ioctl handler,
connector status,
c) handle hdmi audio dynamic power on/off using magic register.

v0.5:
make sure we hit D3 properly
fix fbdev_set_suspend locking interaction, we only will poweroff if we have no
active crtcs/fbcon anyways.
add reference for active crtcs.
sprinkle mark last busy for autosuspend timeout

v0.6:
allow more flexible debugging - to avoid log spam
add option to enable/disable dynpm
got to D3Cold

v0.7:
add hdmi audio support.

v0.8:
call autosuspend from idle, so pci config space access doesn't go straight
back to sleep, this makes starting X faster.
only signal usage if we actually handle the irq, otherwise usb keeps us awake.
fix nv50 display active powerdown

v0.9:
use masking function to enable hdmi audio
set busy when we fail to suspend

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 48 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/dispnv04/crtc.c b/drivers/gpu/drm/nouveau/dispnv04/crtc.c
index 0782bd2..6413552 100644
--- a/drivers/gpu/drm/nouveau/dispnv04/crtc.c
+++ b/drivers/gpu/drm/nouveau/dispnv04/crtc.c
@@ -22,6 +22,7 @@
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  */
+#include <linux/pm_runtime.h>
 
 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
@@ -1007,13 +1008,59 @@ nv04_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 	return 0;
 }
 
+int
+nouveau_crtc_set_config(struct drm_mode_set *set)
+{
+	struct drm_device *dev;
+	struct nouveau_drm *drm;
+	int ret;
+	struct drm_crtc *crtc;
+	bool active = false;
+	if (!set || !set->crtc)
+		return -EINVAL;
+
+	dev = set->crtc->dev;
+
+	/* get a pm reference here */
+	ret = pm_runtime_get_sync(dev->dev);
+	if (ret < 0)
+		return ret;
+
+	ret = drm_crtc_helper_set_config(set);
+
+	drm = nouveau_drm(dev);
+
+	/* if we get here with no crtcs active then we can drop a reference */
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		if (crtc->enabled)
+			active = true;
+	}
+
+	pm_runtime_mark_last_busy(dev->dev);
+	/* if we have active crtcs and we don't have a power ref,
+	   take the current one */
+	if (active && !drm->have_disp_power_ref) {
+		drm->have_disp_power_ref = true;
+		return ret;
+	}
+	/* if we have no active crtcs, then drop the power ref
+	   we got before */
+	if (!active && drm->have_disp_power_ref) {
+		pm_runtime_put_autosuspend(dev->dev);
+		drm->have_disp_power_ref = false;
+	}
+	/* drop the power reference we got coming in here */
+	pm_runtime_put_autosuspend(dev->dev);
+	return ret;
+}
+
 static const struct drm_crtc_funcs nv04_crtc_funcs = {
 	.save = nv_crtc_save,
 	.restore = nv_crtc_restore,
 	.cursor_set = nv04_crtc_cursor_set,
 	.cursor_move = nv04_crtc_cursor_move,
 	.gamma_set = nv_crtc_gamma_set,
-	.set_config = drm_crtc_helper_set_config,
+	.set_config = nouveau_crtc_set_config,
 	.page_flip = nouveau_crtc_page_flip,
 	.destroy = nv_crtc_destroy,
 };