Re: [PATCH 2/2] drm/xe/configfs: Fix 'undefined reference to xe_configfs_...' errors

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 22 Dec 2025, Michal Wajdeczko <michal.wajdeczko@intel.com> wrote:
> On configs where Xe is built-in (DRM_XE=y) but configfs is defined
> as a module (CONFIGFS=m), we were not enabling our configfs stubs,
> which might lead to the following build errors:
>
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_guc.o: in function `xe_guc_init_post_hwconfig':
>    xe_guc.c:(.text+0x2f08): undefined reference to `xe_configfs_get_psmi_enabled'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_hw_engine.o: in function `xe_hw_engines_init_early':
>    xe_hw_engine.c:(.text+0xedc): undefined reference to `xe_configfs_get_engines_allowed'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_lrc.o: in function `setup_configfs_post_ctx_restore_bb':
>    xe_lrc.c:(.text+0xb30): undefined reference to `xe_configfs_get_ctx_restore_post_bb'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_lrc.o: in function `setup_configfs_mid_ctx_restore_bb':
>    xe_lrc.c:(.text+0xbc0): undefined reference to `xe_configfs_get_ctx_restore_mid_bb'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_lrc.o: in function `xe_lrc_init':
>    xe_lrc.c:(.text+0x32fc): undefined reference to `xe_configfs_get_ctx_restore_mid_bb'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_module.o:(.data.rel.ro+0x10): undefined reference to `xe_configfs_init'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_module.o:(.data.rel.ro+0x18): undefined reference to `xe_configfs_exit'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_pci.o: in function `xe_pci_probe':
>    xe_pci.c:(.text+0x1514): undefined reference to `xe_configfs_check_device'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_psmi.o: in function `xe_psmi_debugfs_register':
>    xe_psmi.c:(.text+0x508): undefined reference to `xe_configfs_get_psmi_enabled'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_psmi.o: in function `xe_psmi_init':
>    xe_psmi.c:(.text+0x5c4): undefined reference to `xe_configfs_get_psmi_enabled'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_rtp.o: in function `xe_rtp_match_psmi_enabled':
>    xe_rtp.c:(.text+0xba0): undefined reference to `xe_configfs_get_psmi_enabled'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_survivability_mode.o: in function `xe_survivability_mode_is_requested':
>    xe_survivability_mode.c:(.text+0x434): undefined reference to `xe_configfs_get_survivability_mode'
>    powerpc64-linux-ld: drivers/gpu/drm/xe/xe_sriov_pf.o: in function `xe_sriov_pf_readiness':
>    xe_sriov_pf.c:(.text+0x2a0): undefined reference to `xe_configfs_get_max_vfs'
>
> Fix that by using IS_REACHABLE check instead of IS_ENABLED when
> deciding whether to stub variant or not.

Please avoid IS_REACHABLE() like the plague. It allows build but is
unlikely to result in a configuration or end result that anyone
wants. It also results in bug reports that are tedious to figure
out. The problem should be solved at kconfig time.

Again, the solution is

	depends on CONFIGFS_FS || !CONFIGFS_FS


BR,
Jani.


> Fixes: 16280ded45fb ("drm/xe: Add configfs to enable survivability mode")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202512190407.CcUFXX2F-lkp@intel.com/
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Cc: Riana Tauro <riana.tauro@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_configfs.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_configfs.h b/drivers/gpu/drm/xe/xe_configfs.h
> index 9998ec7c9956..ab75485b08b6 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.h
> +++ b/drivers/gpu/drm/xe/xe_configfs.h
> @@ -12,7 +12,7 @@
>  
>  struct pci_dev;
>  
> -#if IS_ENABLED(CONFIG_CONFIGFS_FS)
> +#if IS_REACHABLE(CONFIG_CONFIGFS_FS)
>  int xe_configfs_init(void);
>  void xe_configfs_exit(void);
>  void xe_configfs_check_device(struct pci_dev *pdev);

-- 
Jani Nikula, Intel