drm/v3d: Suppress all but the first MMU error

The v3d driver currently encounters a lot of MMU PTE exceptions, so
only log the first to avoid swamping the kernel log.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

drivers/gpu/drm/v3d/v3d_irq.c

@@ -177,6 +177,7 @@ v3d_hub_irq(int irq, void *arg)
 			"GMP",
 		};
 		const char *client = "?";
+		static int logged_error;
 
 		V3D_WRITE(V3D_MMU_CTL, V3D_READ(V3D_MMU_CTL));
 
@@ -186,6 +187,7 @@ v3d_hub_irq(int irq, void *arg)
 				client = v3d41_axi_ids[axi_id];
 		}
 
+		if (!logged_error)
 		dev_err(v3d->dev, "MMU error from client %s (%d) at 0x%llx%s%s%s\n",
 			client, axi_id, (long long)vio_addr,
 			((intsts & V3D_HUB_INT_MMU_WRV) ?
@@ -194,6 +196,7 @@ v3d_hub_irq(int irq, void *arg)
 			 ", pte invalid" : ""),
 			((intsts & V3D_HUB_INT_MMU_CAP) ?
 			 ", cap exceeded" : ""));
+		logged_error = 1;
 		status = IRQ_HANDLED;
 	}