mirror_ubuntu-kernels/include
Simon Ser ec5722adb8
drm/fourcc: document modifier uniqueness requirements
There have suggestions to bake pitch alignment, address alignment,
contiguous memory or other placement (hidden VRAM, GTT/BAR, etc)
constraints into modifiers. Last time this was brought up it seemed
like the consensus was to not allow this. Document this in drm_fourcc.h.

There are several reasons for this.

- Encoding all of these constraints in the modifiers would explode the
  search space pretty quickly (we only have 64 bits to work with).
- Modifiers need to be unambiguous: a buffer can only have a single
  modifier.
- Modifier users aren't expected to parse modifiers (except drivers).

v2: add paragraph about aliases (Daniel)

v3: fix unrelated changes sent with the patch

v4: disambiguate users between driver and higher-level programs (Brian,
Daniel)

v5: fix AFBC example (Brian, Daniel)

v6: remove duplicated paragraph (Daniel)

Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Marek Olšák <maraeo@gmail.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Michel Dänzer <michel@daenzer.net>
Link: https://patchwork.freedesktop.org/patch/msgid/MGwgeXojKNdNXjCxuMhRlwcJM4vdYph_WJcMeGPPGMcRKtHV41XAXlh2tCc-pPJZCAhS3gwbWMWTd8f03NBA2ZYKfr0QxLhcPivpopr5c6M=@emersion.fr
2020-10-09 11:39:19 +02:00
..
acpi
asm-generic iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
clocksource include/: replace HTTP links with HTTPS ones 2020-08-12 10:57:59 -07:00
crypto mm, treewide: rename kzfree() to kfree_sensitive() 2020-08-07 11:33:22 -07:00
drm drm/atomic: Pass the full state to CRTC atomic enable/disable 2020-10-09 09:55:59 +02:00
dt-bindings Here's some more updates that missed the last pull request because I 2020-08-12 12:19:49 -07:00
keys
kunit
kvm
linux dma-buf: Document struct dma_buf_map 2020-09-29 12:41:27 +02:00
math-emu treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
media media updates for v5.9-rc1 2020-08-07 13:00:53 -07:00
memory
misc
net RxRPC fixes 2020-08-27 12:55:46 -07:00
pcmcia
ras
rdma RDMA 5.9 merge window pull request 2020-08-06 16:43:36 -07:00
scsi
soc irqchip/eznps: Fix build error for !ARC700 builds 2020-08-27 13:15:17 -07:00
sound
target
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-03 18:50:48 -07:00
uapi drm/fourcc: document modifier uniqueness requirements 2020-10-09 11:39:19 +02:00
vdso lib/vdso: Allow to add architecture-specific vdso data 2020-08-06 10:57:30 +02:00
video fbdev: remove mbx framebuffer driver 2020-09-08 13:33:32 +02:00
xen xen: branch for v5.9-rc4 2020-09-06 09:59:27 -07:00