drm/vc4: Enable/Disable vblanks properly in crtc en/disable.

Add missing drm_crtc_vblank_on/off() calls so vblank irq
handling/updating/timestamping never runs with a crtc shut down
or during its shutdown/startup, as that causes large jumps in
vblank count and trouble for compositors.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 7ffdad543ed2cbb588ad8f2037620bde7bb25e95..2682f07d8f1e6d3dc89ad0858f136c511040b517 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -475,6 +475,9 @@ static void vc4_crtc_disable(struct drm_crtc *crtc)
        int ret;
        require_hvs_enabled(dev);
 
+       /* Disable vblank irq handling before crtc is disabled. */
+       drm_crtc_vblank_off(crtc);
+
        CRTC_WRITE(PV_V_CONTROL,
                   CRTC_READ(PV_V_CONTROL) & ~PV_VCONTROL_VIDEN);
        ret = wait_for(!(CRTC_READ(PV_V_CONTROL) & PV_VCONTROL_VIDEN), 1);
@@ -525,6 +528,9 @@ static void vc4_crtc_enable(struct drm_crtc *crtc)
        /* Turn on the pixel valve, which will emit the vstart signal. */
        CRTC_WRITE(PV_V_CONTROL,
                   CRTC_READ(PV_V_CONTROL) | PV_VCONTROL_VIDEN);
+
+       /* Enable vblank irq handling after crtc is started. */
+       drm_crtc_vblank_on(crtc);
 }
 
 static bool vc4_crtc_mode_fixup(struct drm_crtc *crtc,