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 */