[Intel-gfx] [PATCH 1/1] drm/vblank: drop use of DRM_WAIT_ON()

[Sam Ravnborg]

>From e6f70cb90e0c3c90d45017a8257353652b7e0dcc Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam at ravnborg.org>
Date: Thu, 30 May 2019 09:38:47 +0200
Subject: [PATCH] drm/vblank: drop use of DRM_WAIT_ON()

DRM_WAIT_ON() is from the deprecated drm_os_linux header and
the modern replacement is the wait_event_*.

The return values differ, so a conversion is needed to
keep the original interface towards userspace.
Introduced a switch/case to make code obvious and to allow
different debug prints depending on the result.

Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
Reviewed-by: Sean Paul <sean at poorly.run>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <maxime.ripard at bootlin.com>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
---

To verify if it works with the fix.
(Added wat variable to handle the situation where we never wait)

	Sam

 drivers/gpu/drm/drm_vblank.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 603ab105125d..4e83f1dfd446 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -31,7 +31,6 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_print.h>
-#include <drm/drm_os_linux.h>
 #include <drm/drm_vblank.h>
 
 #include "drm_internal.h"
@@ -1576,7 +1575,7 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
 	struct drm_crtc *crtc;
 	struct drm_vblank_crtc *vblank;
 	union drm_wait_vblank *vblwait = data;
-	int ret;
+	int ret, wait;
 	u64 req_seq, seq;
 	unsigned int pipe_index;
 	unsigned int flags, pipe, high_pipe;
@@ -1669,22 +1668,35 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
 		return drm_queue_vblank_event(dev, pipe, req_seq, vblwait, file_priv);
 	}
 
+	wait = 1;
 	if (req_seq != seq) {
 		DRM_DEBUG("waiting on vblank count %llu, crtc %u\n",
 			  req_seq, pipe);
-		DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
-			    vblank_passed(drm_vblank_count(dev, pipe),
-					  req_seq) ||
-			    !READ_ONCE(vblank->enabled));
+		wait = wait_event_interruptible_timeout(vblank->queue,
+			vblank_passed(drm_vblank_count(dev, pipe), req_seq) ||
+				      !READ_ONCE(vblank->enabled),
+			msecs_to_jiffies(3000));
 	}
 
-	if (ret != -EINTR) {
+	switch (wait) {
+	case 0:
+		/* timeout */
+		ret = -EBUSY;
 		drm_wait_vblank_reply(dev, pipe, &vblwait->reply);
-
-		DRM_DEBUG("crtc %d returning %u to client\n",
+		DRM_DEBUG("timeout waiting for vblank. crtc %d returning %u to client\n",
 			  pipe, vblwait->reply.sequence);
-	} else {
+		break;
+	case -ERESTARTSYS:
+		/* interrupted by signal */
+		ret = -EINTR;
 		DRM_DEBUG("crtc %d vblank wait interrupted by signal\n", pipe);
+		break;
+	default:
+		ret = 0;
+		drm_wait_vblank_reply(dev, pipe, &vblwait->reply);
+		DRM_DEBUG("crtc %d returning %u to client\n",
+			  pipe, vblwait->reply.sequence);
+		break;
 	}
 
 done:
-- 
2.20.1