fb: fsync() method for deferred I/O flush.
There are cases when we do not want to wait on the delay for automatically
updating the "real" framebuffer, this implements a simple ->fsync() hook
for explicitly flushing the deferred I/O work. The ->page_mkwrite()
handler will rearm the work queue normally.
(akpm: nuke unneeded ifdefs, forward-delcare struct dentry)
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Acked-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
index 65f4e6e..f963f5f 100644
--- a/drivers/video/fb_defio.c
+++ b/drivers/video/fb_defio.c
@@ -47,6 +47,18 @@
return page;
}
+int fb_deferred_io_fsync(struct file *file, struct dentry *dentry, int datasync)
+{
+ struct fb_info *info = file->private_data;
+
+ /* Kill off the delayed work */
+ cancel_rearming_delayed_work(&info->deferred_work);
+
+ /* Run it immediately */
+ return schedule_delayed_work(&info->deferred_work, 0);
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_fsync);
+
/* vm_ops->page_mkwrite handler */
static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
struct page *page)
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index 2822526..44cf0e4 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1266,6 +1266,9 @@
#ifdef HAVE_ARCH_FB_UNMAPPED_AREA
.get_unmapped_area = get_fb_unmapped_area,
#endif
+#ifdef CONFIG_FB_DEFERRED_IO
+ .fsync = fb_deferred_io_fsync,
+#endif
};
struct class *fb_class;
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 8a8255b..0de4260 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -4,6 +4,8 @@
#include <asm/types.h>
#include <linux/i2c.h>
+struct dentry;
+
/* Definitions of frame buffers */
#define FB_MAJOR 29
@@ -927,11 +929,11 @@
}
}
-#ifdef CONFIG_FB_DEFERRED_IO
/* drivers/video/fb_defio.c */
extern void fb_deferred_io_init(struct fb_info *info);
extern void fb_deferred_io_cleanup(struct fb_info *info);
-#endif
+extern int fb_deferred_io_fsync(struct file *file, struct dentry *dentry,
+ int datasync);
/* drivers/video/fbsysfs.c */
extern struct fb_info *framebuffer_alloc(size_t size, struct device *dev);