From: Geert Uytterhoeven <geert@linux-m68k.org>
To: "Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
"Maxime Ripard" <mripard@kernel.org>,
"Thomas Zimmermann" <tzimmermann@suse.de>,
"David Airlie" <airlied@linux.ie>,
"Daniel Vetter" <daniel@ffwll.ch>,
"Noralf Trønnes" <noralf@tronnes.org>,
"Gerd Hoffmann" <kraxel@redhat.com>
Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH 1/3] drm/fourcc: Add missing big-endian XRGB1555 and RGB565 formats
Date: Fri, 8 Jul 2022 20:21:07 +0200 [thread overview]
Message-ID: <0744671ac096a12f0d538906bd324efa71b11400.1657300532.git.geert@linux-m68k.org> (raw)
In-Reply-To: <cover.1657300532.git.geert@linux-m68k.org>
As of commit eae06120f1974e1a ("drm: refuse ADDFB2 ioctl for broken
bigendian drivers"), drivers must set the
quirk_addfb_prefer_host_byte_order quirk to make the drm_mode_addfb()
compat code work correctly on big-endian machines.
While that works fine for big-endian XRGB8888 and ARGB8888, which are
mapped to the existing little-endian BGRX8888 and BGRA8888 formats, it
does not work for big-endian XRGB1555 and RGB565, as the latter are not
listed in the format database.
Fix this by adding the missing formats. Limit this to big-endian
platforms, as there is currently no need to support these formats on
little-endian platforms.
Fixes: 6960e6da9cec3f66 ("drm: fix drm_mode_addfb() on big endian machines.")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
Cirrus is the only driver setting quirk_addfb_prefer_host_byte_order
and supporting RGB565 or XRGB1555, but no one tried that on big-endian?
Cirrus does not support DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN
in cirrus_fb_create, so you cannot get a graphical text console.
Do we need these definitions on little-endian platforms, too?
Would it be better to use "DRM_FORMAT_{XRGB1555,RGB565} |
DRM_FORMAT_BIG_ENDIAN" instead of "DRM_FORMAT_HOST_{XRGB1555,RGB565}" in
formats[]?
Alternative, callers could filter out the DRM_FORMAT_BIG_ENDIAN flag
when calling {,__}drm_format_info().
Advantages:
- No need to have separate entries with DRM_FORMAT_BIG_ENDIAN set.
Disadvantages:
- {,__}drm_format_info() returns a pointer to a const object,
whose .format field won't have the DRM_FORMAT_BIG_ENDIAN flag set,
complicating callers,
- All callers need to be updated,
- It is difficult to know which big-endian formats are really
supported, especially as only a few are needed.
---
drivers/gpu/drm/drm_fourcc.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index e09331bb3bc73f21..16a854c9e07fa4b0 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -190,6 +190,10 @@ const struct drm_format_info *__drm_format_info(u32 format)
{ .format = DRM_FORMAT_BGRA5551, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
{ .format = DRM_FORMAT_RGB565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
{ .format = DRM_FORMAT_BGR565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+#ifdef __BIG_ENDIAN
+ { .format = DRM_FORMAT_HOST_XRGB1555, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+ { .format = DRM_FORMAT_HOST_RGB565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
+#endif
{ .format = DRM_FORMAT_RGB888, .depth = 24, .num_planes = 1, .cpp = { 3, 0, 0 }, .hsub = 1, .vsub = 1 },
{ .format = DRM_FORMAT_BGR888, .depth = 24, .num_planes = 1, .cpp = { 3, 0, 0 }, .hsub = 1, .vsub = 1 },
{ .format = DRM_FORMAT_XRGB8888, .depth = 24, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
--
2.25.1
next prev parent reply other threads:[~2022-07-08 18:22 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-08 18:21 [PATCH 0/3] drm: Endianness fixes Geert Uytterhoeven
2022-07-08 18:21 ` Geert Uytterhoeven [this message]
2022-07-11 15:22 ` [PATCH 1/3] drm/fourcc: Add missing big-endian XRGB1555 and RGB565 formats Michel Dänzer
2022-07-11 15:30 ` Geert Uytterhoeven
2022-07-11 16:28 ` Michel Dänzer
2022-07-12 7:47 ` Gerd Hoffmann
2022-07-12 8:01 ` Geert Uytterhoeven
2022-07-12 8:39 ` Gerd Hoffmann
2022-07-12 8:43 ` Geert Uytterhoeven
2022-07-12 9:03 ` Gerd Hoffmann
2022-07-12 9:09 ` Michel Dänzer
2022-07-12 9:10 ` Geert Uytterhoeven
2022-07-12 8:31 ` Gerd Hoffmann
2022-07-08 18:21 ` [PATCH 2/3] drm/format-helper: Fix endianness in drm_fb_*_to_*() conversion helpers Geert Uytterhoeven
2022-07-08 18:21 ` [PATCH 3/3] drm/gud: Fix endianness in gud_xrgb8888_to_color() helper Geert Uytterhoeven
2022-07-19 14:39 ` Noralf Trønnes
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