diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 62087028a..d2ad45c10 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -260,7 +260,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
 	if (err == 0) {
 		spin_unlock(&line->lock);
 		return IRQ_NONE;
-	} else if (err < 0) {
+	} else if ((err < 0) && (err != -EAGAIN)) {
 		line->head = line->buffer;
 		line->tail = line->buffer;
 	}