Revert "drm/fb-helper: Schedule deferred-I/O worker after writing to framebuffer"

This reverts commit 7f5cc4a3e5e4c5a38e5748defc952e45278f7a70.

Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a
Link: https://patchwork.freedesktop.org/patch/msgid/20221118133535.9739-3-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c0e9a977a3b3c35123b5fa76249dfb68e32acd0e..cdbf03e941b2bdfbf2ed0b92c1b81ade7c91e8ac 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -599,16 +599,9 @@ static void drm_fb_helper_add_damage_clip(struct drm_fb_helper *helper, u32 x, u
 static void drm_fb_helper_damage(struct drm_fb_helper *helper, u32 x, u32 y,
                                 u32 width, u32 height)
 {
-       struct fb_info *info = helper->info;
-
        drm_fb_helper_add_damage_clip(helper, x, y, width, height);
 
-       /*
-        * The current fbdev emulation only flushes buffers if a damage
-        * update is necessary. And we can assume that deferred I/O has
-        * been enabled as damage updates require deferred I/O for mmap.
-        */
-       fb_deferred_io_schedule_flush(info);
+       schedule_work(&helper->damage_work);
 }
 
 /*

diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index dec678f72a42f674fce64f422732111957740536..c730253ab85cee86a796aa784179bfb13c3c4b7a 100644 (file)
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -332,19 +332,3 @@ void fb_deferred_io_cleanup(struct fb_info *info)
        mutex_destroy(&fbdefio->lock);
 }
 EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
-
-void fb_deferred_io_schedule_flush(struct fb_info *info)
-{
-       struct fb_deferred_io *fbdefio = info->fbdefio;
-
-       if (WARN_ON_ONCE(!fbdefio))
-               return; /* bug in driver logic */
-
-       /*
-        * There's no requirement from callers to schedule the
-        * flush immediately. Rather schedule the worker with a
-        * delay and let a few more writes pile up.
-        */
-       schedule_delayed_work(&info->deferred_work, fbdefio->delay);
-}
-EXPORT_SYMBOL_GPL(fb_deferred_io_schedule_flush);

diff --git a/include/linux/fb.h b/include/linux/fb.h
index a2a52f7309890cf417451012649dd37c24341914..64889a2b783f38a418bce5cb5f3e442b2d77605c 100644 (file)
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -663,7 +663,6 @@ extern void fb_deferred_io_open(struct fb_info *info,
                                struct inode *inode,
                                struct file *file);
 extern void fb_deferred_io_cleanup(struct fb_info *info);
-extern void fb_deferred_io_schedule_flush(struct fb_info *info);
 extern int fb_deferred_io_fsync(struct file *file, loff_t start,
                                loff_t end, int datasync);