drm/tidss: Add printing of underflows

Add printing of underflows the same way as we handle sync losts.

Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Reviewed-by: Aradhya Bhatia <aradhya.bhatia@linux.dev>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241021-tidss-irq-fix-v1-4-82ddaec94e4a@ideasonboard.com

drivers/gpu/drm/tidss/tidss_irq.c

@@ -78,6 +78,14 @@ static irqreturn_t tidss_irq_handler(int irq, void *arg)
 			tidss_crtc_error_irq(crtc, irqstatus);
 	}
 
+	for (unsigned int i = 0; i < tidss->num_planes; ++i) {
+		struct drm_plane *plane = tidss->planes[i];
+		struct tidss_plane *tplane = to_tidss_plane(plane);
+
+		if (irqstatus & DSS_IRQ_PLANE_FIFO_UNDERFLOW(tplane->hw_plane_id))
+			tidss_plane_error_irq(plane, irqstatus);
+	}
+
 	return IRQ_HANDLED;
 }
 
@@ -112,6 +120,12 @@ int tidss_irq_install(struct drm_device *ddev, unsigned int irq)
 		tidss->irq_mask |= DSS_IRQ_VP_FRAME_DONE(tcrtc->hw_videoport);
 	}
 
+	for (unsigned int i = 0; i < tidss->num_planes; ++i) {
+		struct tidss_plane *tplane = to_tidss_plane(tidss->planes[i]);
+
+		tidss->irq_mask |= DSS_IRQ_PLANE_FIFO_UNDERFLOW(tplane->hw_plane_id);
+	}
+
 	return 0;
 }
 

drivers/gpu/drm/tidss/tidss_plane.c

@@ -18,6 +18,14 @@
 #include "tidss_drv.h"
 #include "tidss_plane.h"
 
+void tidss_plane_error_irq(struct drm_plane *plane, u64 irqstatus)
+{
+	struct tidss_plane *tplane = to_tidss_plane(plane);
+
+	dev_err_ratelimited(plane->dev->dev, "Plane%u underflow (irq %llx)\n",
+			    tplane->hw_plane_id, irqstatus);
+}
+
 /* drm_plane_helper_funcs */
 
 static int tidss_plane_atomic_check(struct drm_plane *plane,

drivers/gpu/drm/tidss/tidss_plane.h

@@ -22,4 +22,6 @@ struct tidss_plane *tidss_plane_create(struct tidss_device *tidss,
 				       u32 crtc_mask, const u32 *formats,
 				       u32 num_formats);
 
+void tidss_plane_error_irq(struct drm_plane *plane, u64 irqstatus);
+
 #endif