Re: [PATCH] drm: xe: select configfs

[Raag Jadav]

On Fri, Nov 13, 2026 at 08:22:12AM -0800, Matt Roper wrote:
> On Wed, Nov 11, 2026 at 02:01:45PM -0500, Rodrigo Vivi wrote:
> > On Mon, Oct 26, 2026 at 11:25:50AM +0100, Arnd Bergmann wrote:
> > > From: Arnd Bergmann <arnd@xxxxxxxx>
> > > 
> > > The original addition of configfs to xe missed a compile-time dependency,
> > > which leads to a link failure when configfs is enabled as a loadable module:
> > > 
> > > ld.lld-21: error: undefined symbol: xe_configfs_get_survivability_mode
> > > >>> referenced by xe_survivability_mode.c:224
> > > >>>               drivers/gpu/drm/xe/xe_survivability_mode.o:(xe_survivability_mode_is_requested) in archive vmlinux.a
> > > 
> > > A recent workaround added a 'IS_REACHABLE()' check around the calls into
> > > configfs, which makes it link in this configuration, but this is generally
> > > a bad idea because it makes the actual behavior inconsistent and confusing
> > > to users that expect configfs to work if both xe and configfs are enabled.
> > > 
> > > Use 'select CONFIGFS_FS' instead, like every other configfs user does,
> > > and remove the unnecessary stub functions. There is little practical
> > > difference here as anyone using XE graphics is likely to have a complex
> > > configuration that already selects configfs anyway, and the link error
> > > or the IS_REACHABLE() would only manifest during randconfig testing.
> > > 
> > > Fixes: 30499cbd7961 ("drm/xe: Fix build with DRM_XE=y and CONFIGFS_FS=m")
> > > Fixes: 16280ded45fb ("drm/xe: Add configfs to enable survivability mode")
> > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > > ---
> > >  drivers/gpu/drm/xe/Kconfig       |  1 +
> > >  drivers/gpu/drm/xe/xe_configfs.h | 30 ------------------------------
> > >  2 files changed, 1 insertion(+), 30 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
> > > index 4fc8abdc5cb6..b52a8dc28f97 100644
> > > --- a/drivers/gpu/drm/xe/Kconfig
> > > +++ b/drivers/gpu/drm/xe/Kconfig
> > > @@ -11,6 +11,7 @@ config DRM_XE
> > >  	# the shmem_readpage() which depends upon tmpfs
> > >  	select SHMEM
> > >  	select TMPFS
> > > +	select CONFIGFS_FS
> > 
> > Perhaps another option would be what Jani had suggested:
> > 
> > config DRM_XE_CONFIGFS
> > 	def_bool y
> > 	depends on DRM_XE && CONFIGFS_FS
> > 	depends on CONFIGFS_FS=y || DRM_XE=m
> > 
> > But anyway, we are depending more and more on the configfs for
> > production choices. So, let's go with you select and close this
> > for good.
> 
> I really don't think this patch was the way we wanted to go.
> IS_REACHABLE was giving us exactly the behavior that we wanted, but now
> we're getting behavior that we did not want.  Xe absolutely does not
> depend on configfs in any way.  _If_ configfs is there we'll enable some
> config options in it, but none of those are mandatory for our driver as
> a whole.  We're perfectly happy to build and run without configfs if
> it's not selected in the config.  We're also happy to build and run
> without configfs functionality if the user wanted Xe built directly into
> the kernel, but configfs was built as an unreachable module solely for
> other non-Xe purposes.
> 
> While this change won't matter to 99% of the cases where someone is
> running with a typical distro kernel, this is the kind of thing that
> makes embedded users unhappy since they're very carefully managing their
> configurations and we've taken away their ability to avoid configfs now.

+1'ing on this. People go to great lengths to save a few bytes, only to
be undone by a non-essential config.

Raag