From cc3283f8f41f741fbaef63d0503d8fb4a7919100 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Sun, 10 Jan 2021 13:51:03 +0100
Subject: [PATCH] drm/fourcc: fix Amlogic format modifier masks
Git-commit: cc3283f8f41f741fbaef63d0503d8fb4a7919100
Patch-mainline: v5.12-rc1
References: git-fixes
The comment says the layout and options use 8 bits, and the shift
uses 8 bits. However the mask is 0xf, ie. 0b00001111 (4 bits).
This could be surprising when introducing new layouts or options
that take more than 4 bits, as this would silently drop the high
bits.
Make the masks consistent with the comment and the shift.
Found when writing a drm_info patch [1].
[1]: https://github.com/ascent12/drm_info/pull/67
Signed-off-by: Simon Ser <contact@emersion.fr>
Fixes: d6528ec88309 ("drm/fourcc: Add modifier definitions for describing Amlogic Video Framebuffer Compression")
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210110125103.15447-1-contact@emersion.fr
Acked-by: Takashi Iwai <tiwai@suse.de>
---
include/uapi/drm/drm_fourcc.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 723c8e23ca87..5f42a14481bd 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -1036,9 +1036,9 @@ drm_fourcc_canonicalize_nvidia_format_mod(__u64 modifier)
* Not all combinations are valid, and different SoCs may support different
* combinations of layout and options.
*/
-#define __fourcc_mod_amlogic_layout_mask 0xf
+#define __fourcc_mod_amlogic_layout_mask 0xff
#define __fourcc_mod_amlogic_options_shift 8
-#define __fourcc_mod_amlogic_options_mask 0xf
+#define __fourcc_mod_amlogic_options_mask 0xff
#define DRM_FORMAT_MOD_AMLOGIC_FBC(__layout, __options) \
fourcc_mod_code(AMLOGIC, \
--
2.26.2