Re: [PATCH v4] drm/xe: Allow building as kernel built-in

[Harry Austen <hpausten@protonmail.com>]

On Wed May 21, 2025 at 4:11 PM BST, Lucas De Marchi wrote:
> On Wed, May 21, 2025 at 08:35:05AM +0000, Harry Austen wrote:
> >On Mon May 19, 2025 at 4:14 PM BST, Maarten Lankhorst wrote:
> >> Hey,
> >>
> >> On 2025-05-16 12:42, Harry Austen wrote:
> >>> Fix Kconfig symbol dependency on KUNIT, which isn't actually required
> >>> for XE to be built-in. However, if KUNIT is enabled, it must be built-in
> >>> too.
> >>>
> >>> Also, allow DRM_XE_DISPLAY to be built-in. But only as long as DRM_I915
> >>> isn't, since that results in duplicate symbol errors.
> >>>
> >>> Fixes: 08987a8b6820 ("drm/xe: Fix build with KUNIT=m")
> >>> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> >>> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> >>> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> >>> Signed-off-by: Harry Austen <hpausten@protonmail.com>
> >>> Acked-by: Jani Nikula <jani.nikula@intel.com>
> >>> ---
> >>> v4: Add Jani Nikula's Acked-by tag
> >>> v3: Simplify KUNIT dependency, as suggested by Jani Nikula
> >>> v2: Ensure DRM_XE_DISPLAY and DRM_I915 can't both be built-in
> >>>
> >>>  drivers/gpu/drm/xe/Kconfig | 5 +++--
> >>>  1 file changed, 3 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
> >>> index 9bce047901b22..214f40264fa12 100644
> >>> --- a/drivers/gpu/drm/xe/Kconfig
> >>> +++ b/drivers/gpu/drm/xe/Kconfig
> >>> @@ -1,7 +1,8 @@
> >>>  # SPDX-License-Identifier: GPL-2.0-only
> >>>  config DRM_XE
> >>>  	tristate "Intel Xe Graphics"
> >>> -	depends on DRM && PCI && MMU && (m || (y && KUNIT=y))
> >>> +	depends on DRM && PCI && MMU
> >>> +	depends on KUNIT || KUNIT=n
> >>>  	select INTERVAL_TREE
> >>>  	# we need shmfs for the swappable backing store, and in particular
> >>>  	# the shmem_readpage() which depends upon tmpfs
> >>> @@ -51,7 +52,7 @@ config DRM_XE
> >>>
> >>>  config DRM_XE_DISPLAY
> >>>  	bool "Enable display support"
> >>> -	depends on DRM_XE && DRM_XE=m && HAS_IOPORT
> >>> +	depends on DRM_XE && (DRM_XE=m || DRM_I915!=y) && HAS_IOPORT
> >>>  	select FB_IOMEM_HELPERS if DRM_FBDEV_EMULATION
> >>>  	select I2C
> >>>  	select I2C_ALGOBIT
> >> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> >
> >Thanks!
> >
> >>
> >> Can we also get rid of the IOSF_MBI select? Not even xe_display depends on it, leftover from initial porting. :)
> >
> >As this seems unrelated, I'd be happy to submit a separate patch for this
> >afterwards. Thanks for the suggestion.
>
> same comment as in the previous version of this patch. What I don't like
> is that it doesn't prevent you to do a bad selection. Instead if you set
> DRM_XE=y and DRM_I915=y, you lose DRM_XE_DISPLAY. Silently. This is
> equivalent of chosing the options via make menuconfig:
>
> 	# initial state
> 	./scripts/config --state CONFIG_DRM_XE --state CONFIG_DRM_XE_DISPLAY --state CONFIG_DRM_I915
> 	m
> 	y
> 	m
>
> 	# set CONFIG_DRM_XE to built-in
> 	./scripts/config -e CONFIG_DRM_XE && make -s olddefconfig
> 	./scripts/config --state CONFIG_DRM_XE --state CONFIG_DRM_XE_DISPLAY --state CONFIG_DRM_I915
> 	y
> 	y
> 	m
>
> 	# set CONFIG_DRM_I915 to built-in, we lose display with xe
> 	$ ~/p/linux-dim/drm-xe-next/scripts/config --state CONFIG_DRM_XE --state CONFIG_DRM_XE_DISPLAY --state CONFIG_DRM_I915
> 	y
> 	undef
> 	y
>
> I'm not sure how to prevent setting CONFIG_DRM_I915=y if
> CONFIG_DRM_XE_DISPLAY is selected.

Ah interesting, thanks for the example. I'll try a few different things and see
if I can get more sensible behaviour.

>
> Lucas De Marchi
>
> >
> >Harry
> >