[PATCH 5/5] drm/imx: only enable vblank IRQs when needed

[Lucas Stach]

The vblank IRQ is only needed to trigger page flip work, so we
might as well disable it when there is no work to do.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 drivers/gpu/drm/imx/ipuv3-crtc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/imx/ipuv3-crtc.c b/drivers/gpu/drm/imx/ipuv3-crtc.c
index 30214c0e7d93..3d842715755d 100644
--- a/drivers/gpu/drm/imx/ipuv3-crtc.c
+++ b/drivers/gpu/drm/imx/ipuv3-crtc.c
@@ -382,11 +382,18 @@ static const struct drm_crtc_helper_funcs 
ipu_helper_funcs = {

 static int ipu_enable_vblank(struct drm_crtc *crtc)
 {
+       struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
+
+       enable_irq(ipu_crtc->irq);
+
        return 0;
 }

 static void ipu_disable_vblank(struct drm_crtc *crtc)
 {
+       struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
+
+       disable_irq_nosync(ipu_crtc->irq);
 }

 static int ipu_set_interface_pix_fmt(struct drm_crtc *crtc,
@@ -497,6 +504,8 @@ static int ipu_crtc_init(struct ipu_crtc *ipu_crtc,
                dev_err(ipu_crtc->dev, "irq request failed with %d.\n", ret);
                goto err_put_plane_res;
        }
+       /* Only enable IRQ when we actually need it to trigger work. */
+       disable_irq(ipu_crtc->irq);

        ipu_crtc->flip_queue = create_singlethread_workqueue("ipu-crtc-flip");

-- 
2.7.0.rc3