| Message ID | 20230127093631.2132187-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | accel: work around DRM_ACCEL dependencies | expand |
Hi On Fri, Jan 27, 2023 at 10:36:20AM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > At the moment, accel drivers can be built-in even with CONFIG_DRM=m, > but this causes a link failure: > > x86_64-linux-ld: drivers/accel/ivpu/ivpu_drv.o: in function `ivpu_dev_init': > ivpu_drv.c:(.text+0x1535): undefined reference to `drmm_kmalloc' > x86_64-linux-ld: ivpu_drv.c:(.text+0x1562): undefined reference to `drmm_kmalloc' > x86_64-linux-ld: drivers/accel/ivpu/ivpu_drv.o: in function `ivpu_remove': > ivpu_drv.c:(.text+0x1faa): undefined reference to `drm_dev_unregister' > x86_64-linux-ld: drivers/accel/ivpu/ivpu_drv.o: in function `ivpu_probe': > ivpu_drv.c:(.text+0x1fef): undefined reference to `__devm_drm_dev_alloc' Ehh, this should not happen. > This could be avoided by making DRM_ACCEL a tristate symbol, which > would mean that every ACCEL driver is guarantee to be able to link > against DRM as well. However, having both as =m causes another link > failure because the DRM core code also links against the accel driver: > > x86_64-linux-ld: drivers/gpu/drm/drm_drv.o: in function `drm_minor_register': > drm_drv.c:(.text+0x259): undefined reference to `accel_debugfs_init' > x86_64-linux-ld: drm_drv.c:(.text+0x298): undefined reference to `accel_minor_replace' > > I think it will be necessary to establish a link hierarchy between drm.ko > and drm_accel.ko to avoid circular dependencies like this, but until then > the only way that both can be used is to have both subsystems built into > the kernel. Enforce this using a Kconfig dependency. Hmm, it was discussed a bit before and conclusion was that accel will be compiled in drm.ko to avoid circular dependencies. There should be no drm_accel.ko module. > Fixes: 8bf4889762a8 ("drivers/accel: define kconfig and register a new major") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > drivers/accel/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig > index 834863902e16..dd18d3b2028c 100644 > --- a/drivers/accel/Kconfig > +++ b/drivers/accel/Kconfig > @@ -8,7 +8,7 @@ > # > menuconfig DRM_ACCEL > bool "Compute Acceleration Framework" > - depends on DRM > + depends on DRM=y Would making ivpu Kconfig: depends on DRM select DRM_ACCEL solve the problem and still allow to drm to be build as module ? Regards Stanislaw
On Fri, Jan 27, 2023, at 11:17, Stanislaw Gruszka wrote: > On Fri, Jan 27, 2023 at 10:36:20AM +0100, Arnd Bergmann wrote: >> I think it will be necessary to establish a link hierarchy between drm.ko >> and drm_accel.ko to avoid circular dependencies like this, but until then >> the only way that both can be used is to have both subsystems built into >> the kernel. Enforce this using a Kconfig dependency. > > Hmm, it was discussed a bit before and conclusion was that accel will be > compiled in drm.ko to avoid circular dependencies. There should be > no drm_accel.ko module. Ok, got it. This does not sounds like a great solution as it ties the two modules closer together than most users want, but it should work as long as we control the dependencies for the individual drivers. >> diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig >> index 834863902e16..dd18d3b2028c 100644 >> --- a/drivers/accel/Kconfig >> +++ b/drivers/accel/Kconfig >> @@ -8,7 +8,7 @@ >> # >> menuconfig DRM_ACCEL >> bool "Compute Acceleration Framework" >> - depends on DRM >> + depends on DRM=y > > Would making ivpu Kconfig: > > depends on DRM > select DRM_ACCEL > > solve the problem and still allow to drm to be build as module ? Right, that should work, I'll send a v2 patch to add an "if DRM" around the entire drivers/accel/Kconfig file, which should have the effect. Arnd
diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig index 834863902e16..dd18d3b2028c 100644 --- a/drivers/accel/Kconfig +++ b/drivers/accel/Kconfig @@ -8,7 +8,7 @@ # menuconfig DRM_ACCEL bool "Compute Acceleration Framework" - depends on DRM + depends on DRM=y help Framework for device drivers of compute acceleration devices, such as, but not limited to, Machine-Learning and Deep-Learning