MLK-18767: drm: imx: dcss: fix vblank timed out warning

The following commit:

f9a03b3 - MLK-17925: drm: imx: dcss: fix tearing

introduced a regression because we does not send VBLANK event if context
loader was not flushed. But this condition is always met immediately
after enabling the CRTC. Hence, when 30FPS modes are selected, it is
possible to exceed the 50ms vblank timeout if the first event is not
sent. That's because 2 x 0.33ms > 50ms. This does not happen for 60fps
modes though.

This patch will force sending the first vblank event even if the context
loader is not completely flushed.

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>

diff --git a/drivers/gpu/drm/imx/dcss/dcss-crtc.c b/drivers/gpu/drm/imx/dcss/dcss-crtc.c
index 5e9366a..0cf149d 100644 (file)
--- a/drivers/gpu/drm/imx/dcss/dcss-crtc.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-crtc.c
@@ -49,6 +49,8 @@ struct dcss_crtc {
        enum dcss_hdr10_gamut opipe_g;
        enum dcss_hdr10_pixel_range opipe_pr;
        u32 opipe_pix_format;
+
+       bool fist_vblank_after_en;
 };
 
 static void dcss_crtc_reset(struct drm_crtc *crtc)
@@ -245,6 +247,8 @@ static void dcss_crtc_atomic_enable(struct drm_crtc *crtc,
        dcss_dtg_enable(dcss, true, NULL);
        dcss_ctxld_enable(dcss);
 
+       dcss_crtc->fist_vblank_after_en = true;
+
        crtc->enabled = true;
 }
 
@@ -264,8 +268,6 @@ static void dcss_crtc_atomic_disable(struct drm_crtc *crtc,
        }
        spin_unlock_irq(&crtc->dev->event_lock);
 
-       drm_crtc_vblank_off(crtc);
-
        dcss_ss_enable(dcss, false);
        dcss_dtg_enable(dcss, false, &dcss_crtc->disable_completion);
        dcss_ctxld_enable(dcss);
@@ -275,6 +277,8 @@ static void dcss_crtc_atomic_disable(struct drm_crtc *crtc,
        wait_for_completion_timeout(&dcss_crtc->disable_completion,
                                    msecs_to_jiffies(100));
 
+       drm_crtc_vblank_off(crtc);
+
        pm_runtime_put_sync(dcss_crtc->dev->parent);
 }
 
@@ -293,8 +297,10 @@ static irqreturn_t dcss_crtc_irq_handler(int irq, void *dev_id)
 
        dcss_trace_module(TRACE_DRM_CRTC, TRACE_VBLANK);
 
-       if (dcss_ctxld_is_flushed(dcss))
+       if (dcss_ctxld_is_flushed(dcss) || dcss_crtc->fist_vblank_after_en) {
                drm_crtc_handle_vblank(&dcss_crtc->base);
+               dcss_crtc->fist_vblank_after_en = false;
+       }
 
        dcss_vblank_irq_clear(dcss);