From cd9f7f7ac5932129fe81b4c7559cfcb226ec7c5c Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Tue, 1 Feb 2022 12:53:05 +0100
Subject: drm/fb-helper: Mark screen buffers in system memory with
 FBINFO_VIRTFB
Git-commit: cd9f7f7ac5932129fe81b4c7559cfcb226ec7c5c
Patch-mainline: v5.18-rc1
References: bsc#1129770

Mark screen buffers in system memory with FBINFO_VIRTFB. Otherwise, fbdev
deferred I/O marks mmap'ed areas of system memory with VM_IO. (There's an
inverse relationship between the two flags.)

For shadow buffers, also set the FBINFO_READS_FAST hint.

v3:
	* change FB_ to FBINFO_ in commit description
v2:
	* updated commit description (Daniel)
	* added Fixes tag

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: d536540f304c ("drm/fb-helper: Add generic fbdev emulation .fb_probe function")
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.19+
Link: https://patchwork.freedesktop.org/patch/msgid/20220201115305.9333-1-tzimmermann@suse.de
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_fb_helper.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -3083,6 +3083,7 @@ int drm_fb_helper_generic_probe(struct d
 	fbi->fix.smem_len = fbi->screen_size;
 	fbi->screen_buffer = buffer->vaddr;
 	strcpy(fbi->fix.id, "DRM emulated");
+	fbi->flags = FBINFO_DEFAULT;
 
 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
 	drm_fb_helper_fill_var(fbi, fb_helper, sizes->fb_width, sizes->fb_height);
@@ -3106,6 +3107,7 @@ int drm_fb_helper_generic_probe(struct d
 		*fbops = *fbi->fbops;
 		fbi->fbops = fbops;
 		fbi->screen_buffer = shadow;
+		fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
 		fbi->fbdefio = &drm_fbdev_defio;
 
 		fb_deferred_io_init(fbi);