[PATCH] drm/i915: Autoselect CONFIG_CHECKPOINT_RESTORE for SYS_kcmp

[Chris Wilson]

gallium (iris) depends on os_same_file_description() to disambiguate
screens and so avoid importing the same screen fd twice as two distinct
entities (that share all the kernel resources, so actions on screen
affect the other and would cause random faiure). As they depend on it,
so must we. os_same_file_description() uses SYS_kcmp to check the file
tables for the equivalent struct file, but SYS_kcmp is hidden behind
CONFIG_CHECKPOINT_RESTORE. As this is not default, we must select it for
ourselves to ensure that our userspace is fully supported.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3046
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 1e1cb245fca7..470a5214bd33 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -21,6 +21,7 @@ config DRM_I915
 	select ACPI_VIDEO if ACPI
 	select ACPI_BUTTON if ACPI
 	select SYNC_FILE
+	select CHECKPOINT_RESTORE # gallium depends on SYS_kcmp
 	select IOSF_MBI
 	select CRC32
 	select SND_HDA_I915 if SND_HDA_CORE
-- 
2.20.1