From dba8746636e35f3e42bed62f5b7d7231adf569c8 Mon Sep 17 00:00:00 2001
From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Date: Wed, 4 Apr 2018 21:55:21 +0300
Subject: [PATCH v100500 9/9] UDL: add pseudo deferred io for modeset driver

With blackjack and mud.
---
 drivers/gpu/drm/udl/udl_modeset.c | 42 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index 5bcae7649795..737471da16e4 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -17,6 +17,45 @@
 #include <drm/drm_plane_helper.h>
 #include "udl_drv.h"
 
+/* All hacks and mud stuff --- start */
+#define DL_DEFIO_WRITE_DELAY    (HZ / 40) /* deferred_io delay in jiffies */
+
+static struct delayed_work deferred_work;
+static struct drm_device *deferred_dev;
+
+static void pal_modeset_damage(struct drm_device *dev)
+{
+	struct udl_device *udl = dev->dev_private;
+	struct udl_framebuffer *ufb;
+
+	if (!udl->crtc || !udl->crtc->primary->fb)
+		return;
+
+	ufb = to_udl_fb(udl->crtc->primary->fb);
+	udl_handle_damage(ufb, 0, 0, ufb->base.width, ufb->base.height);
+}
+
+static void pal_deferred_io_work(struct work_struct *work)
+{
+	pal_modeset_damage(deferred_dev);
+	schedule_delayed_work(&deferred_work, DL_DEFIO_WRITE_DELAY);
+}
+
+static void pal_deferred_io_cleanup(void)
+{
+	cancel_delayed_work_sync(&deferred_work);
+}
+
+static void pal_deferred_io_init(struct drm_device *dev)
+{
+	deferred_dev = dev;
+
+	INIT_DELAYED_WORK(&deferred_work, pal_deferred_io_work);
+
+	schedule_delayed_work(&deferred_work, DL_DEFIO_WRITE_DELAY);
+}
+/* All hacks and mud stuff --- end */
+
 /*
  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  * All operations are written to buffers which then later get sent to device
@@ -450,6 +489,8 @@ int udl_modeset_init(struct drm_device *dev)
 
 	udl_connector_init(dev, encoder);
 
+	pal_deferred_io_init(dev);
+
 	return 0;
 }
 
@@ -467,5 +508,6 @@ void udl_modeset_restore(struct drm_device *dev)
 
 void udl_modeset_cleanup(struct drm_device *dev)
 {
+	pal_deferred_io_cleanup();
 	drm_mode_config_cleanup(dev);
 }
-- 
2.14.3