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#1152472

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 |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2104,6 +2104,7 @@ static int drm_fb_helper_generic_probe(s
 	fbi->fbops = &drm_fbdev_fb_ops;
 	fbi->screen_size = fb->height * fb->pitches[0];
 	fbi->fix.smem_len = fbi->screen_size;
+	fbi->flags = FBINFO_DEFAULT;
 
 	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
 
@@ -2111,9 +2112,9 @@ static int drm_fb_helper_generic_probe(s
 		fbi->screen_buffer = vzalloc(fbi->screen_size);
 		if (!fbi->screen_buffer)
 			return -ENOMEM;
+		fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
 
 		fbi->fbdefio = &drm_fbdev_defio;
-
 		fb_deferred_io_init(fbi);
 	} else {
 		/* buffer is mapped for HW framebuffer */