From: Max Staudt <mstaudt@xxxxxxx>
This callback from fb_open() allows a fbdev driver to adjust things such
as file->f_mapping to better represent the internal structures.
This is needed to allow TTM drivers using ttm_fbdev_mmap() to properly
set file->f_mapping to TTM's address_space from bo->bdev->dev_mapping,
as is done form /dev/drm/card* in drm_open().
Currently, bochsdrmfb is the only driver requiring this, and this
patch is a prerequisite to implement this in bochsdrmfb.
Signed-off-by: Max Staudt <mstaudt@xxxxxxx>
---
drivers/video/fbdev/core/fbmem.c | 13 +++++++++++++
include/linux/fb.h | 7 +++++++
2 files changed, 20 insertions(+)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 913c496..ff5000e 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1471,6 +1471,19 @@ __releases(&info->lock)
if (info->fbdefio)
fb_deferred_io_open(info, inode, file);
#endif
+ if (info->fbops->fb_open_adj_file) {
+ res = info->fbops->fb_open_adj_file(info, file);
+ if (res) {
+ /* If we got here, we also want to undo anything
+ * that fbops->fb_open() may have done.
+ */
+ if (info->fbops->fb_release)
+ info->fbops->fb_release(info,1);
+
+ module_put(info->fbops->owner);
+ goto out;
+ }
+ }
out:
mutex_unlock(&info->lock);
if (res)
diff --git a/include/linux/fb.h b/include/linux/fb.h
index dfe8835..4131496 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -320,6 +320,13 @@ struct fb_ops {
/* called at KDB enter and leave time to prepare the console */
int (*fb_debug_enter)(struct fb_info *info);
int (*fb_debug_leave)(struct fb_info *info);
+
+ /* Called after fb_open() to adjust mappings when using
+ * complex backends such as TTM.
+ * For example, the bochsdrmfb driver needs to adjust
+ * file->f_mapping so it can use ttm_fbdev_mmap().
+ */
+ int (*fb_open_adj_file)(struct fb_info *info, struct file *file);
};
#ifdef CONFIG_FB_TILEBLITTING
--
2.6.6
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