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Marijn Suijten 887fec2c28
tests/util: Call drmGetDevices2() instead of drmOpen()ing all modules
Whenever `util_open()` is called to open a device for the first matching
module, it will skip devices for the `nvidia_drm` kernel module which
is not in the list.  We could add this module for now, but keeping this
list of DRM modules up to date is cumbersome.

At the same time walking a list of modules and calling `drmOpen()` for
each of them is incredibly expensive (when the user doesn't explicitly
specify one with `-M`), as each each call opens every DRM node just
to see if they are associated to the requested module.  And for no
good reason: all we want is the first `DRM_NODE_PRIMARY` (which is what
`drmOpen()` also returns) to use by default.

For example on the `"msm"` driver, which used to be the 9th in the
modules list, all nodes are opened for the 9th time before e.g.
`modetest` returns a useful result, which takes ages unless the user
painstakingly provides the module for the currently known device on
the cmdline.

This is very simply solved by calling `drmGetDevices(2)()`, which
iterates through all DRM nodes only once and allows us to immediately
find + `open()` the first device that has a PRIMARY node.  A random
search for the error shows that this was also attempted in (a fork of?)
kmscube:
https://git.ti.com/cgit/glsdk/kmscube/commit/?id=456cabc661caac5c60729751d45efd668faa8e97

Finally we add a `drmIsKMS()` check to make sure we only include primary
nodes that actually support rendering, and also print the values from
`drmGetVersion()` on success to make it easier to identify the device.

In the future we could extrapolate this feature by letting query
commands like `modetest -c` list connectors for every device/module, not
just the first PRIMARY node that we found.
2024-09-03 13:30:41 +02:00
amdgpu libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
android android: Fix 32-bit app crashing in 64-bit Android 2018-12-18 21:18:19 +01:00
data Convert to Android.bp 2024-07-29 14:47:30 -04:00
etnaviv libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
exynos libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
freedreno libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
include/drm Sync headers with drm-next 2024-06-26 08:08:40 +00:00
intel libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
man man: Add formatting to drmModeGetConnector reference 2022-04-19 13:13:13 -07:00
nouveau libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
omap libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
radeon libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
tegra libs: Tie DSO minor versions to libdrm version 2024-08-01 13:28:41 +01:00
tests tests/util: Call drmGetDevices2() instead of drmOpen()ing all modules 2024-09-03 13:30:41 +02:00
vc4 Delete all Makefile.sources files 2024-07-30 10:54:23 -04:00
.editorconfig Add meson build system 2018-01-12 09:40:48 -08:00
.gitignore add a minimal .gitignore back 2019-12-17 22:37:39 +00:00
.gitlab-ci.yml ci: upgrade FreeBSD VM to 14.1 2024-06-25 12:57:01 +02:00
Android.bp Enable GPU in crosvm 2024-07-30 10:54:34 -04:00
Android.sources.bp Convert to Android.bp 2024-07-29 14:47:30 -04:00
Android.sources.bp.mk Convert to Android.bp 2024-07-29 14:47:30 -04:00
CleanSpec.mk tests: Split helpers into library 2015-12-18 17:43:40 +00:00
CONTRIBUTING.rst doc: Rename README&CONTRIBUTING to .rst 2018-10-17 17:17:19 +02:00
core-symbols.txt xf86drmMode: add drmModeCloseFB() 2023-11-20 12:55:31 +00:00
gen_table_fourcc.py gen_table_fourcc: strip _MODIFIER suffix for INVALID 2022-06-08 14:02:48 +02:00
libdrm.pc.in Revert "Fix pkgconfig includes for /usr/include/drm" 2010-04-09 16:33:38 -04:00
libdrm_lists.h use standard __typeof__() instead of GNU extension typeof() 2022-01-19 16:08:31 -08:00
libdrm_macros.h libdrm: Use mmap64 instead of __mmap2 2019-04-25 10:55:13 +01:00
libsync.h include poll.h instead of sys/poll.h 2024-04-10 23:27:16 +00:00
meson.build build: bump version to 2.4.123 2024-08-26 13:10:22 -07:00
meson_options.txt meson: auto-enable etnaviv on arm, arc, mips and loongarch architectures 2022-08-30 16:03:36 +01:00
README.rst README.rst: Include some notes about syncing uapi headers 2021-06-22 11:16:04 +00:00
RELEASING releasing: s/master/main/ 2021-12-21 13:07:01 +00:00
symbols-check.py symbols-check: Add _fbss, _fdata, _ftext 2024-03-25 15:35:58 +00:00
util_double_list.h use standard __typeof__() instead of GNU extension typeof() 2022-01-19 16:08:31 -08:00
util_math.h Fix build with -std=c11 2018-09-05 13:09:29 +01:00
xf86atomic.h atomic: fix atomic_add_unless() fallback's return value 2022-08-23 22:49:34 +00:00
xf86drm.c OpenBSD: fix FTBS on misspelled and missing variables 2024-06-24 12:57:51 +02:00
xf86drm.h xf86drm: document drmDevicesEqual() 2024-04-11 12:11:30 +02:00
xf86drmHash.c xf86drmHash: remove unused loop variable 2018-11-09 10:59:11 +00:00
xf86drmHash.h tests/hash: extract test out of xf86drmHash.c 2015-04-05 15:19:42 +01:00
xf86drmMode.c xf86drmMode: add drmModeCloseFB() 2023-11-20 12:55:31 +00:00
xf86drmMode.h xf86drmMode: add drmModeCloseFB() 2023-11-20 12:55:31 +00:00
xf86drmRandom.c libdrm: annotate public functions 2018-09-19 22:46:45 -07:00
xf86drmRandom.h tests/random: extract test out of xf86drmRandom.c 2015-04-05 15:33:33 +01:00
xf86drmSL.c libdrm: annotate public functions 2018-09-19 22:46:45 -07:00

libdrm - userspace library for drm
----------------------------------

This is libdrm, a userspace library for accessing the DRM, direct rendering
manager, on Linux, BSD and other operating systems that support the ioctl
interface.
The library provides wrapper functions for the ioctls to avoid exposing the
kernel interface directly, and for chipsets with drm memory manager, support
for tracking relocations and buffers.
New functionality in the kernel DRM drivers typically requires a new libdrm,
but a new libdrm will always work with an older kernel.

libdrm is a low-level library, typically used by graphics drivers such as
the Mesa drivers, the X drivers, libva and similar projects.

Syncing with the Linux kernel headers
-------------------------------------

The library should be regularly updated to match the recent changes in the
`include/uapi/drm/`.

libdrm maintains a human-readable version for the token format modifier, with
the simpler ones being extracted automatically from `drm_fourcc.h` header file
with the help of a python script.  This might not always possible, as some of
the vendors require decoding/extracting them programmatically.  For that
reason one can enhance the current vendor functions to include/provide the
newly added token formats, or, in case there's no such decoding
function, to add one that performs the tasks of extracting them.

For simpler format modifier tokens there's a script (gen_table_fourcc.py) that
creates a static table, by going over `drm_fourcc.h` header file. The script
could be further modified if it can't handle new (simpler) token format
modifiers instead of the generated static table.

Compiling
---------

To set up meson:

    meson builddir/

By default this will install into /usr/local, you can change your prefix
with --prefix=/usr (or `meson configure builddir/ -Dprefix=/usr` after 
the initial meson setup).

Then use ninja to build and install:

    ninja -C builddir/ install

If you are installing into a system location you will need to run install
separately, and as root.