From b9fb2a21ac8058965a6b3fcae736cfa7f411d6eb Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Wed, 9 Nov 2016 13:36:36 +0100
Subject: [PATCH] drm_fourcc: Document linear modifier
Not setting the fb modifiers flag is something different from setting
the fb modifiers to 0 (which means explicitly linear). We kinda failed
to document that properly. Spotted by Kristian.
Cc: hoegsberg@google.com
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1478694996-4200-1-git-send-email-daniel.vetter@ffwll.ch
---
include/uapi/drm/drm_fourcc.h | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index a5890bf44c0af..0ccef30e56b61 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -172,6 +172,16 @@ extern "C" {
* authoritative source for all of these.
*/
+/*
+ * Linear Layout
+ *
+ * Just plain linear layout. Note that this is different from no specifying any
+ * modifier (e.g. not setting DRM_MODE_FB_MODIFIERS in the DRM_ADDFB2 ioctl),
+ * which tells the driver to also take driver-internal information into account
+ * and so might actually result in a tiled framebuffer.
+ */
+#define DRM_FORMAT_MOD_LINEAR fourcc_mod_code(NONE, 0)
+
/* Intel framebuffer modifiers */
/*
--
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