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FAILED: patch "[PATCH] drm/fb-helper: Mark screen buffers in system memory with" failed to apply to 5.4-stable tree

PATCH [email protected] 1 participant 1 message Apr 2, 2022

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The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From cd9f7f7ac5932129fe81b4c7559cfcb226ec7c5c Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <[email protected]>
Date: Tue, 1 Feb 2022 12:53:05 +0100
Subject: [PATCH] drm/fb-helper: Mark screen buffers in system memory with
FBINFO_VIRTFB

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 <[email protected]>
Fixes d536540f304c ("drm/fb-helper: Add generic fbdev emulation .fb_probe function")
Reviewed-by Daniel Vetter <[email protected]>
Cc [email protected]
Cc <[email protected]> # v4.19+
Link https://patchwork.freedesktop.org/patch/msgid/[email protected]
drivers/gpu/drm/drm_fb_helper.c +6 -3
index 9727a59d35fd..805c5a666490 100644
@@ -2340,6 +2340,7 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
 	fbi->fbops = &drm_fbdev_fb_ops;
 	fbi->screen_size = sizes->surface_height * fb->pitches[0];
 	fbi->fix.smem_len = fbi->screen_size;
+	fbi->flags = FBINFO_DEFAULT;
 
 	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
 

@@ -2347,19 +2348,21 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
 		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 */
 		ret = drm_client_buffer_vmap(fb_helper->buffer, &map);
 		if (ret)
 			return ret;
-		if (map.is_iomem)
+		if (map.is_iomem) {
 			fbi->screen_base = map.vaddr_iomem;
-		else
+		} else {
 			fbi->screen_buffer = map.vaddr;
+			fbi->flags |= FBINFO_VIRTFB;
+		}
 
 		/*
 		 * Shamelessly leak the physical address to user-space. As