drm/vc4: Disable overrun interrupts

We have a read-modify-write race when updating SCALER_DISPCTRL for
underrun and end-of-frame interrupts.
Ideally it would be fixed via a spinlock or similar, but that will
require a reasonable amount of study to ensure we don't get deadlocks.

The underrun reporting is only for debug, so disable it for now.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 1003976..b86b5dc 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -868,7 +868,7 @@ static void vc4_crtc_handle_page_flip(struct vc4_crtc *vc4_crtc)
                 * the CRTC and encoder already reconfigured, leading to
                 * underruns. This can be seen when reconfiguring the CRTC.
                 */
-               if (vc4->gen < VC4_GEN_6)
+               if (0 && vc4->gen < VC4_GEN_6)
                        vc4_hvs_unmask_underrun(hvs, chan);
        }
        spin_unlock(&vc4_crtc->irq_lock);

diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
index 964ecf5..ea66914 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -391,7 +391,7 @@ static void vc4_atomic_commit_tail(struct drm_atomic_state *state)
        if (WARN_ON(IS_ERR(new_hvs_state)))
                return;
 
-       if (vc4->gen < VC4_GEN_6) {
+       if (0 && vc4->gen < VC4_GEN_6) {
                struct drm_crtc_state *new_crtc_state;
                struct drm_crtc *crtc;
                int i;