[PATCH 3/4] vmwgfx: Wrap drm_read and drm_poll

[Thomas Hellstrom]

Make sure the device is processing the fifo when these functions are
called in case they might sleep waiting for an event.

Signed-off-by: Thomas Hellstrom <thellstrom at vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c   |    3 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.h   |    4 +++
 drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c |   43 +++++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 5e1994a..e07dcf4 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -1085,7 +1085,8 @@ static struct drm_driver driver = {
 		 .release = drm_release,
 		 .unlocked_ioctl = vmw_unlocked_ioctl,
 		 .mmap = vmw_mmap,
-		 .poll = drm_poll,
+		 .poll = vmw_fops_poll,
+		 .read = vmw_fops_read,
 		 .fasync = drm_fasync,
 #if defined(CONFIG_COMPAT)
 		 .compat_ioctl = drm_compat_ioctl,
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 83b2563..0e9b2ce 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -469,6 +469,10 @@ extern int vmw_present_ioctl(struct drm_device *dev, void *data,
 			     struct drm_file *file_priv);
 extern int vmw_present_readback_ioctl(struct drm_device *dev, void *data,
 				      struct drm_file *file_priv);
+extern unsigned int vmw_fops_poll(struct file *filp,
+				  struct poll_table_struct *wait);
+extern ssize_t vmw_fops_read(struct file *filp, char __user *buffer,
+			     size_t count, loff_t *offset);
 
 /**
  * Fifo utilities - vmwgfx_fifo.c
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
index c0284a4..97f23ab 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
@@ -282,3 +282,46 @@ out_no_copy:
 out_clips:
 	return ret;
 }
+
+
+/**
+ * vmw_fops_poll - wrapper around the drm_poll function
+ *
+ * @filp: See the linux fops poll documentation.
+ * @wait: See the linux fops poll documentation.
+ *
+ * Wrapper around the drm_poll function that makes sure the device is
+ * processing the fifo if drm_poll decides to wait.
+ */
+unsigned int vmw_fops_poll(struct file *filp, struct poll_table_struct *wait)
+{
+	struct drm_file *file_priv = filp->private_data;
+	struct vmw_private *dev_priv =
+		vmw_priv(file_priv->minor->dev);
+
+	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
+	return drm_poll(filp, wait);
+}
+
+
+/**
+ * vmw_fops_read - wrapper around the drm_read function
+ *
+ * @filp: See the linux fops read documentation.
+ * @buffer: See the linux fops read documentation.
+ * @count: See the linux fops read documentation.
+ * offset: See the linux fops read documentation.
+ *
+ * Wrapper around the drm_read function that makes sure the device is
+ * processing the fifo if drm_read decides to wait.
+ */
+ssize_t vmw_fops_read(struct file *filp, char __user *buffer,
+		      size_t count, loff_t *offset)
+{
+	struct drm_file *file_priv = filp->private_data;
+	struct vmw_private *dev_priv =
+		vmw_priv(file_priv->minor->dev);
+
+	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
+	return drm_read(filp, buffer, count, offset);
+}
-- 
1.7.4.4