Commit 1ab4de28 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

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



This reverts commit 7f5cc4a3.

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: default avatarThomas Zimmermann <tzimmermann@suse.de>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
Link: https://patchwork.freedesktop.org/patch/msgid/20221118133535.9739-3-tzimmermann@suse.de
(cherry picked from commit 8b83e1a4)
parent 713befe8

drivers/gpu/drm/drm_fb_helper.c

+1 −8
Original line number Diff line number Diff line
@@ -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);

}



/*

drivers/video/fbdev/core/fb_defio.c

+0 −16
Original line number Diff line number Diff line
@@ -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);

include/linux/fb.h

+0 −1
Original line number Diff line number Diff line
@@ -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);