Share drm resources between X and early camera

Early camera module will open drm before X, so when X starts up,
it should share the mapping address with early camera rather than
reopen it again. Normally, X will call drm_release when system
shutdown. At that time, early camera has already quitted and
released the drm resources. So it does not need to do resource
check in drm_release.

Change-Id: I692e111d76bf76c0a3faaac15f89e9ef8b261114
Signed-off-by: Fang, Neo <neo.fang@intel.com>

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 7f2af9a..08ae115 100644 (file)
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -85,7 +85,7 @@ int drm_open(struct inode *inode, struct file *filp)
        int retcode = 0;
        int need_setup = 0;
        struct address_space *old_mapping;
-       struct address_space *old_imapping;
+       static int is1st = 1;
 
        minor = idr_find(&drm_minors_idr, minor_id);
        if (!minor)
@@ -100,12 +100,17 @@ int drm_open(struct inode *inode, struct file *filp)
        if (!dev->open_count++)
                need_setup = 1;
        mutex_lock(&dev->struct_mutex);
-       old_imapping = inode->i_mapping;
        old_mapping = dev->dev_mapping;
-       if (old_mapping == NULL)
+
+       if (is1st) {
                dev->dev_mapping = &inode->i_data;
-       /* ihold ensures nobody can remove inode with our i_data */
+               is1st = 0;
+       } else {
+               if (old_mapping == NULL)
+                       dev->dev_mapping = &inode->i_data;
+       }
        ihold(container_of(dev->dev_mapping, struct inode, i_data));
+
        inode->i_mapping = dev->dev_mapping;
        filp->f_mapping = dev->dev_mapping;
        mutex_unlock(&dev->struct_mutex);
@@ -122,8 +127,8 @@ int drm_open(struct inode *inode, struct file *filp)
 
 err_undo:
        mutex_lock(&dev->struct_mutex);
-       filp->f_mapping = old_imapping;
-       inode->i_mapping = old_imapping;
+       filp->f_mapping = old_mapping;
+       inode->i_mapping = old_mapping;
        iput(container_of(dev->dev_mapping, struct inode, i_data));
        dev->dev_mapping = old_mapping;
        mutex_unlock(&dev->struct_mutex);