diff mbox series

drm: rcar-du: fix linker undefined references

Message ID 20210423213727.27751-1-rdunlap@infradead.org (mailing list archive)
State New, archived
Headers show
Series drm: rcar-du: fix linker undefined references | expand

Commit Message

Randy Dunlap April 23, 2021, 9:37 p.m. UTC
When DRM_RCAR_DU=y and DRM_RCAR_LVDS=m, there are several build errors
as reported by 'kernel test robot'. These can be corrected by changing
"imply" to "select".

In looking at this, the same problem (build errors) happens when
DRM_RCAR_DU=y and DRM_RCAR_CMM=m, so again change the "imply" to
"select" here as well.

These 2 changes fix the following 8 build/link errors:

aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
rcar_du_crtc.c:(.text+0x1be8): undefined reference to `rcar_lvds_clk_enable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
rcar_du_crtc.c:(.text+0x2438): undefined reference to `rcar_lvds_clk_disable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_drv.o: in function `rcar_du_init':
rcar_du_drv.c:(.init.text+0x14): undefined reference to `rcar_du_of_init'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_encoder.o: in function `rcar_du_encoder_init':
rcar_du_encoder.c:(.text+0x1d4): undefined reference to `rcar_lvds_dual_link'

aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_cmm_setup':
rcar_du_crtc.c:(.text+0x380): undefined reference to `rcar_cmm_setup'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
rcar_du_crtc.c:(.text+0x1c08): undefined reference to `rcar_cmm_enable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
rcar_du_crtc.c:(.text+0x231c): undefined reference to `rcar_cmm_disable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_kms.o: in function `rcar_du_modeset_init':
rcar_du_kms.c:(.text+0xd08): undefined reference to `rcar_cmm_init'

Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
Fixes: 02f2b30032c1 ("drm: rcar-du: lvds: Add API to enable/disable clock output")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/gpu/drm/rcar-du/Kconfig |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Laurent Pinchart April 23, 2021, 9:46 p.m. UTC | #1
Hi Randy,

Thank you for the patch.

On Fri, Apr 23, 2021 at 02:37:27PM -0700, Randy Dunlap wrote:
> When DRM_RCAR_DU=y and DRM_RCAR_LVDS=m, there are several build errors
> as reported by 'kernel test robot'. These can be corrected by changing
> "imply" to "select".
> 
> In looking at this, the same problem (build errors) happens when
> DRM_RCAR_DU=y and DRM_RCAR_CMM=m, so again change the "imply" to
> "select" here as well.
> 
> These 2 changes fix the following 8 build/link errors:
> 
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
> rcar_du_crtc.c:(.text+0x1be8): undefined reference to `rcar_lvds_clk_enable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
> rcar_du_crtc.c:(.text+0x2438): undefined reference to `rcar_lvds_clk_disable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_drv.o: in function `rcar_du_init':
> rcar_du_drv.c:(.init.text+0x14): undefined reference to `rcar_du_of_init'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_encoder.o: in function `rcar_du_encoder_init':
> rcar_du_encoder.c:(.text+0x1d4): undefined reference to `rcar_lvds_dual_link'
> 
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_cmm_setup':
> rcar_du_crtc.c:(.text+0x380): undefined reference to `rcar_cmm_setup'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
> rcar_du_crtc.c:(.text+0x1c08): undefined reference to `rcar_cmm_enable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
> rcar_du_crtc.c:(.text+0x231c): undefined reference to `rcar_cmm_disable'
> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_kms.o: in function `rcar_du_modeset_init':
> rcar_du_kms.c:(.text+0xd08): undefined reference to `rcar_cmm_init'
> 
> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
> Fixes: 02f2b30032c1 ("drm: rcar-du: lvds: Add API to enable/disable clock output")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Reported-by: kernel test robot <lkp@intel.com>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: linux-renesas-soc@vger.kernel.org
> Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
>  drivers/gpu/drm/rcar-du/Kconfig |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> --- linux-next-20210420.orig/drivers/gpu/drm/rcar-du/Kconfig
> +++ linux-next-20210420/drivers/gpu/drm/rcar-du/Kconfig
> @@ -4,8 +4,8 @@ config DRM_RCAR_DU
>  	depends on DRM && OF
>  	depends on ARM || ARM64
>  	depends on ARCH_RENESAS || COMPILE_TEST
> -	imply DRM_RCAR_CMM
> -	imply DRM_RCAR_LVDS
> +	select DRM_RCAR_CMM
> +	select DRM_RCAR_LVDS

No all platforms that integrate a DU have CMM and/or LVDS support, so we
shouldn't select the automatically.

Would

	depends on DRM_RCAR_CMM || DRM_RCAR_CMM=n
	depends on DRM_RCAR_LVDS || DRM_RCAR_LVDS=n

work ? I thought that's what "imply" meant, but it seems I got it wrong.

>  	select DRM_KMS_HELPER
>  	select DRM_KMS_CMA_HELPER
>  	select DRM_GEM_CMA_HELPER
Randy Dunlap April 23, 2021, 9:56 p.m. UTC | #2
On 4/23/21 2:46 PM, Laurent Pinchart wrote:
> Hi Randy,
> 
> Thank you for the patch.
> 
> On Fri, Apr 23, 2021 at 02:37:27PM -0700, Randy Dunlap wrote:
>> When DRM_RCAR_DU=y and DRM_RCAR_LVDS=m, there are several build errors
>> as reported by 'kernel test robot'. These can be corrected by changing
>> "imply" to "select".
>>
>> In looking at this, the same problem (build errors) happens when
>> DRM_RCAR_DU=y and DRM_RCAR_CMM=m, so again change the "imply" to
>> "select" here as well.
>>
>> These 2 changes fix the following 8 build/link errors:
>>
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
>> rcar_du_crtc.c:(.text+0x1be8): undefined reference to `rcar_lvds_clk_enable'
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
>> rcar_du_crtc.c:(.text+0x2438): undefined reference to `rcar_lvds_clk_disable'
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_drv.o: in function `rcar_du_init':
>> rcar_du_drv.c:(.init.text+0x14): undefined reference to `rcar_du_of_init'
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_encoder.o: in function `rcar_du_encoder_init':
>> rcar_du_encoder.c:(.text+0x1d4): undefined reference to `rcar_lvds_dual_link'
>>
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_cmm_setup':
>> rcar_du_crtc.c:(.text+0x380): undefined reference to `rcar_cmm_setup'
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
>> rcar_du_crtc.c:(.text+0x1c08): undefined reference to `rcar_cmm_enable'
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
>> rcar_du_crtc.c:(.text+0x231c): undefined reference to `rcar_cmm_disable'
>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_kms.o: in function `rcar_du_modeset_init':
>> rcar_du_kms.c:(.text+0xd08): undefined reference to `rcar_cmm_init'
>>
>> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
>> Fixes: 02f2b30032c1 ("drm: rcar-du: lvds: Add API to enable/disable clock output")
>> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Cc: Masahiro Yamada <masahiroy@kernel.org>
>> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>> Cc: dri-devel@lists.freedesktop.org
>> Cc: linux-renesas-soc@vger.kernel.org
>> Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
>> ---
>>   drivers/gpu/drm/rcar-du/Kconfig |    4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> --- linux-next-20210420.orig/drivers/gpu/drm/rcar-du/Kconfig
>> +++ linux-next-20210420/drivers/gpu/drm/rcar-du/Kconfig
>> @@ -4,8 +4,8 @@ config DRM_RCAR_DU
>>   	depends on DRM && OF
>>   	depends on ARM || ARM64
>>   	depends on ARCH_RENESAS || COMPILE_TEST
>> -	imply DRM_RCAR_CMM
>> -	imply DRM_RCAR_LVDS
>> +	select DRM_RCAR_CMM
>> +	select DRM_RCAR_LVDS
> 
> No all platforms that integrate a DU have CMM and/or LVDS support, so we
> shouldn't select the automatically.
> 
> Would
> 
> 	depends on DRM_RCAR_CMM || DRM_RCAR_CMM=n
> 	depends on DRM_RCAR_LVDS || DRM_RCAR_LVDS=n
> 

Looks good; I like it, but kconfig does not:

$ xbuild_arm64.sh  oldconfig
make[1]: Entering directory 
'/home/rdunlap/lnx/next/linux-next-20210420/ARM64'
   GEN     Makefile
drivers/gpu/drm/rcar-du/Kconfig:2:error: recursive dependency detected!
drivers/gpu/drm/rcar-du/Kconfig:2:	symbol DRM_RCAR_DU depends on 
DRM_RCAR_CMM
drivers/gpu/drm/rcar-du/Kconfig:17:	symbol DRM_RCAR_CMM depends on 
DRM_RCAR_DU
For a resolution refer to Documentation/kbuild/kconfig-language.rst
subsection "Kconfig recursive dependency limitations"

> work ? I thought that's what "imply" meant, but it seems I got it wrong.
> 
>>   	select DRM_KMS_HELPER
>>   	select DRM_KMS_CMA_HELPER
>>   	select DRM_GEM_CMA_HELPER
> 


Thanks.
Randy Dunlap April 23, 2021, 10:02 p.m. UTC | #3
On 4/23/21 2:56 PM, Randy Dunlap wrote:
> On 4/23/21 2:46 PM, Laurent Pinchart wrote:
>> Hi Randy,
>>
>> Thank you for the patch.
>>
>> On Fri, Apr 23, 2021 at 02:37:27PM -0700, Randy Dunlap wrote:
>>> When DRM_RCAR_DU=y and DRM_RCAR_LVDS=m, there are several build errors
>>> as reported by 'kernel test robot'. These can be corrected by changing
>>> "imply" to "select".
>>>
>>> In looking at this, the same problem (build errors) happens when
>>> DRM_RCAR_DU=y and DRM_RCAR_CMM=m, so again change the "imply" to
>>> "select" here as well.
>>>
>>> These 2 changes fix the following 8 build/link errors:
>>>
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
>>> `rcar_du_crtc_atomic_enable':
>>> rcar_du_crtc.c:(.text+0x1be8): undefined reference to 
>>> `rcar_lvds_clk_enable'
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
>>> `rcar_du_crtc_atomic_disable':
>>> rcar_du_crtc.c:(.text+0x2438): undefined reference to 
>>> `rcar_lvds_clk_disable'
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_drv.o: in function 
>>> `rcar_du_init':
>>> rcar_du_drv.c:(.init.text+0x14): undefined reference to 
>>> `rcar_du_of_init'
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_encoder.o: in 
>>> function `rcar_du_encoder_init':
>>> rcar_du_encoder.c:(.text+0x1d4): undefined reference to 
>>> `rcar_lvds_dual_link'
>>>
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
>>> `rcar_du_cmm_setup':
>>> rcar_du_crtc.c:(.text+0x380): undefined reference to `rcar_cmm_setup'
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
>>> `rcar_du_crtc_atomic_enable':
>>> rcar_du_crtc.c:(.text+0x1c08): undefined reference to `rcar_cmm_enable'
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
>>> `rcar_du_crtc_atomic_disable':
>>> rcar_du_crtc.c:(.text+0x231c): undefined reference to `rcar_cmm_disable'
>>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_kms.o: in function 
>>> `rcar_du_modeset_init':
>>> rcar_du_kms.c:(.text+0xd08): undefined reference to `rcar_cmm_init'
>>>
>>> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
>>> Fixes: 02f2b30032c1 ("drm: rcar-du: lvds: Add API to enable/disable 
>>> clock output")
>>> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> Cc: Masahiro Yamada <masahiroy@kernel.org>
>>> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>> Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>> Cc: dri-devel@lists.freedesktop.org
>>> Cc: linux-renesas-soc@vger.kernel.org
>>> Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
>>> ---
>>>   drivers/gpu/drm/rcar-du/Kconfig |    4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> --- linux-next-20210420.orig/drivers/gpu/drm/rcar-du/Kconfig
>>> +++ linux-next-20210420/drivers/gpu/drm/rcar-du/Kconfig
>>> @@ -4,8 +4,8 @@ config DRM_RCAR_DU
>>>       depends on DRM && OF
>>>       depends on ARM || ARM64
>>>       depends on ARCH_RENESAS || COMPILE_TEST
>>> -    imply DRM_RCAR_CMM
>>> -    imply DRM_RCAR_LVDS
>>> +    select DRM_RCAR_CMM
>>> +    select DRM_RCAR_LVDS
>>
>> No all platforms that integrate a DU have CMM and/or LVDS support, so we
>> shouldn't select the automatically.
>>
>> Would
>>
>>     depends on DRM_RCAR_CMM || DRM_RCAR_CMM=n
>>     depends on DRM_RCAR_LVDS || DRM_RCAR_LVDS=n
>>
> 
> Looks good; I like it, but kconfig does not:
> 
> $ xbuild_arm64.sh  oldconfig
> make[1]: Entering directory 
> '/home/rdunlap/lnx/next/linux-next-20210420/ARM64'
>    GEN     Makefile
> drivers/gpu/drm/rcar-du/Kconfig:2:error: recursive dependency detected!
> drivers/gpu/drm/rcar-du/Kconfig:2:    symbol DRM_RCAR_DU depends on 
> DRM_RCAR_CMM
> drivers/gpu/drm/rcar-du/Kconfig:17:    symbol DRM_RCAR_CMM depends on 
> DRM_RCAR_DU
> For a resolution refer to Documentation/kbuild/kconfig-language.rst
> subsection "Kconfig recursive dependency limitations"
> 
>> work ? I thought that's what "imply" meant, but it seems I got it wrong.
>>
>>>       select DRM_KMS_HELPER
>>>       select DRM_KMS_CMA_HELPER
>>>       select DRM_GEM_CMA_HELPER
>>

There is some documentation (kconfig-language.rst) that says that when a 
driver Kconfig is using mixed builtin and loadable modules, the driver 
should be using IS_REACHABLE(). The example also uses "imply", so maybe
we should/could try something like that:
If CMM is REACHBLE(), make the calls.
If LVDS is READABLE(), make the calls.

I can look into that some more if you want me to.
Or I'll be happy to let you do so. :)

Thanks.
Laurent Pinchart April 23, 2021, 10:05 p.m. UTC | #4
Hi Randy,

On Fri, Apr 23, 2021 at 03:02:27PM -0700, Randy Dunlap wrote:
> On 4/23/21 2:56 PM, Randy Dunlap wrote:
> > On 4/23/21 2:46 PM, Laurent Pinchart wrote:
> >> On Fri, Apr 23, 2021 at 02:37:27PM -0700, Randy Dunlap wrote:
> >>> When DRM_RCAR_DU=y and DRM_RCAR_LVDS=m, there are several build errors
> >>> as reported by 'kernel test robot'. These can be corrected by changing
> >>> "imply" to "select".
> >>>
> >>> In looking at this, the same problem (build errors) happens when
> >>> DRM_RCAR_DU=y and DRM_RCAR_CMM=m, so again change the "imply" to
> >>> "select" here as well.
> >>>
> >>> These 2 changes fix the following 8 build/link errors:
> >>>
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
> >>> `rcar_du_crtc_atomic_enable':
> >>> rcar_du_crtc.c:(.text+0x1be8): undefined reference to 
> >>> `rcar_lvds_clk_enable'
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
> >>> `rcar_du_crtc_atomic_disable':
> >>> rcar_du_crtc.c:(.text+0x2438): undefined reference to 
> >>> `rcar_lvds_clk_disable'
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_drv.o: in function 
> >>> `rcar_du_init':
> >>> rcar_du_drv.c:(.init.text+0x14): undefined reference to 
> >>> `rcar_du_of_init'
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_encoder.o: in 
> >>> function `rcar_du_encoder_init':
> >>> rcar_du_encoder.c:(.text+0x1d4): undefined reference to 
> >>> `rcar_lvds_dual_link'
> >>>
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
> >>> `rcar_du_cmm_setup':
> >>> rcar_du_crtc.c:(.text+0x380): undefined reference to `rcar_cmm_setup'
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
> >>> `rcar_du_crtc_atomic_enable':
> >>> rcar_du_crtc.c:(.text+0x1c08): undefined reference to `rcar_cmm_enable'
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function 
> >>> `rcar_du_crtc_atomic_disable':
> >>> rcar_du_crtc.c:(.text+0x231c): undefined reference to `rcar_cmm_disable'
> >>> aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_kms.o: in function 
> >>> `rcar_du_modeset_init':
> >>> rcar_du_kms.c:(.text+0xd08): undefined reference to `rcar_cmm_init'
> >>>
> >>> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
> >>> Fixes: 02f2b30032c1 ("drm: rcar-du: lvds: Add API to enable/disable 
> >>> clock output")
> >>> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> >>> Reported-by: kernel test robot <lkp@intel.com>
> >>> Cc: Masahiro Yamada <masahiroy@kernel.org>
> >>> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >>> Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >>> Cc: dri-devel@lists.freedesktop.org
> >>> Cc: linux-renesas-soc@vger.kernel.org
> >>> Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
> >>> ---
> >>>   drivers/gpu/drm/rcar-du/Kconfig |    4 ++--
> >>>   1 file changed, 2 insertions(+), 2 deletions(-)
> >>>
> >>> --- linux-next-20210420.orig/drivers/gpu/drm/rcar-du/Kconfig
> >>> +++ linux-next-20210420/drivers/gpu/drm/rcar-du/Kconfig
> >>> @@ -4,8 +4,8 @@ config DRM_RCAR_DU
> >>>       depends on DRM && OF
> >>>       depends on ARM || ARM64
> >>>       depends on ARCH_RENESAS || COMPILE_TEST
> >>> -    imply DRM_RCAR_CMM
> >>> -    imply DRM_RCAR_LVDS
> >>> +    select DRM_RCAR_CMM
> >>> +    select DRM_RCAR_LVDS
> >>
> >> No all platforms that integrate a DU have CMM and/or LVDS support, so we
> >> shouldn't select the automatically.
> >>
> >> Would
> >>
> >>     depends on DRM_RCAR_CMM || DRM_RCAR_CMM=n
> >>     depends on DRM_RCAR_LVDS || DRM_RCAR_LVDS=n
> > 
> > Looks good; I like it, but kconfig does not:
> > 
> > $ xbuild_arm64.sh  oldconfig
> > make[1]: Entering directory 
> > '/home/rdunlap/lnx/next/linux-next-20210420/ARM64'
> >    GEN     Makefile
> > drivers/gpu/drm/rcar-du/Kconfig:2:error: recursive dependency detected!
> > drivers/gpu/drm/rcar-du/Kconfig:2:    symbol DRM_RCAR_DU depends on 
> > DRM_RCAR_CMM
> > drivers/gpu/drm/rcar-du/Kconfig:17:    symbol DRM_RCAR_CMM depends on 
> > DRM_RCAR_DU
> > For a resolution refer to Documentation/kbuild/kconfig-language.rst
> > subsection "Kconfig recursive dependency limitations"
> > 
> >> work ? I thought that's what "imply" meant, but it seems I got it wrong.
> >>
> >>>       select DRM_KMS_HELPER
> >>>       select DRM_KMS_CMA_HELPER
> >>>       select DRM_GEM_CMA_HELPER
> 
> There is some documentation (kconfig-language.rst) that says that when a 
> driver Kconfig is using mixed builtin and loadable modules, the driver 
> should be using IS_REACHABLE(). The example also uses "imply", so maybe
> we should/could try something like that:
> If CMM is REACHBLE(), make the calls.
> If LVDS is READABLE(), make the calls.
> 
> I can look into that some more if you want me to.
> Or I'll be happy to let you do so. :)

If you have time to have a look, I'd be very happy about that. I can't
promise to repay it with a drink at the next conference, but I hope that
will change sooner than later :-)
diff mbox series

Patch

--- linux-next-20210420.orig/drivers/gpu/drm/rcar-du/Kconfig
+++ linux-next-20210420/drivers/gpu/drm/rcar-du/Kconfig
@@ -4,8 +4,8 @@  config DRM_RCAR_DU
 	depends on DRM && OF
 	depends on ARM || ARM64
 	depends on ARCH_RENESAS || COMPILE_TEST
-	imply DRM_RCAR_CMM
-	imply DRM_RCAR_LVDS
+	select DRM_RCAR_CMM
+	select DRM_RCAR_LVDS
 	select DRM_KMS_HELPER
 	select DRM_KMS_CMA_HELPER
 	select DRM_GEM_CMA_HELPER