Merge tag 'irqchip-urgent-3.19' of git://git.infradead.org/users/jcooper/linux into irq/urgent

irqchip urgent fixes for v3.19 from Jason Cooper
 - mtk-sysirq: Fix error handling
 - hip04: Fix cpu map for 16bit value
 - gic-v3-its: Clear a warning regarding decimal constants
 - omap-intc: Fix legacy DMA regression
 - atmel-aic-common: Retain priority when changing type

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index ed7bc68f7e8..0b9514b6cd6 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -515,16 +515,19 @@ ssize_t drm_read(struct file *filp, char __user *buffer,
 	size_t total;
 	ssize_t ret;
 
-	ret = wait_event_interruptible(file_priv->event_wait,
-				       !list_empty(&file_priv->event_list));
-	if (ret < 0)
-		return ret;
+	if ((filp->f_flags & O_NONBLOCK) == 0) {
+		ret = wait_event_interruptible(file_priv->event_wait,
+					       !list_empty(&file_priv->event_list));
+		if (ret < 0)
+			return ret;
+	}
 
 	total = 0;
 	while (drm_dequeue_event(file_priv, total, count, &e)) {
 		if (copy_to_user(buffer + total,
 				 e->event, e->event->length)) {
 			total = -EFAULT;
+			e->destroy(e);
 			break;
 		}
 
@@ -532,7 +535,7 @@ ssize_t drm_read(struct file *filp, char __user *buffer,
 		e->destroy(e);
 	}
 
-	return total;
+	return total ?: -EAGAIN;
 }
 EXPORT_SYMBOL(drm_read);