From d9d54a530a70eee6f003bd3ade38817cf85b9325 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sun, 27 Oct 2019 15:43:14 +0000
Subject: drm/i915: Put future HW and their uAPIs under STAGING & BROKEN
Git-commit: d9d54a530a70eee6f003bd3ade38817cf85b9325
Patch-mainline: v5.5-rc1
References: bsc#1152489
We would like some freedom to break the user API/ABI for future HW but
yet still expose the driver for upstream development on that HW.
Currently, we have the i915.force_probe module parameter to avoid binding
to HW while the driver is under development, but that is still a little
too soft with respect to the stringent no-regression rules if we also
plan to be redesigning the uAPI to go along with the new HW.
To allow the uAPI to be changed during development, only expose that API
and in development HW under STAGING (and BROKEN). Hopefully, making it
explicit that such interfaces to that HW are under development and not
to be blindly enabled by distributions.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191027154314.11139-1-chris@chris-wilson.co.uk
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/i915/Kconfig | 6 ++++++
drivers/gpu/drm/i915/Kconfig.debug | 1 +
drivers/gpu/drm/i915/Kconfig.unstable | 21 +++++++++++++++++++++
3 files changed, 28 insertions(+)
create mode 100644 drivers/gpu/drm/i915/Kconfig.unstable
diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 3c6d57df262d..ba9595960bbe 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -148,3 +148,9 @@ menu "drm/i915 Profile Guided Optimisation"
depends on DRM_I915
source "drivers/gpu/drm/i915/Kconfig.profile"
endmenu
+
+menu "drm/i915 Unstable Evolution"
+ visible if EXPERT && STAGING && BROKEN
+ depends on DRM_I915
+ source "drivers/gpu/drm/i915/Kconfig.unstable"
+endmenu
diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug
index eea79125b3ea..80815a5229a1 100644
--- a/drivers/gpu/drm/i915/Kconfig.debug
+++ b/drivers/gpu/drm/i915/Kconfig.debug
@@ -36,6 +36,7 @@ config DRM_I915_DEBUG
select DRM_I915_SELFTEST
select DRM_I915_DEBUG_RUNTIME_PM
select DRM_I915_DEBUG_MMIO
+ select BROKEN # for prototype uAPI
default n
help
Choose this option to turn on extra driver debugging that may affect
diff --git a/drivers/gpu/drm/i915/Kconfig.unstable b/drivers/gpu/drm/i915/Kconfig.unstable
new file mode 100644
index 000000000000..cf151a297ed7
--- /dev/null
+++ b/drivers/gpu/drm/i915/Kconfig.unstable
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config DRM_I915_UNSTABLE
+ bool "Enable unstable API for early prototype development"
+ depends on EXPERT
+ depends on STAGING
+ depends on BROKEN # should never be enabled by distros!
+ # We use the dependency on !COMPILE_TEST to not be enabled in
+ # allmodconfig or allyesconfig configurations
+ depends on !COMPILE_TEST
+ default n
+ help
+ Enable prototype uAPI under general discussion before they are
+ finalized. Such prototypes may be withdrawn or substantially
+ changed before release. They are only enabled here so that a wide
+ number of interested parties (userspace driver developers) can
+ verify that the uAPI meet their expectations. These uAPI should
+ never be used in production.
+
+ Recommended for driver developers _only_.
+
+ If in the slightest bit of doubt, say "N".
--
2.28.0