Re: gpu: drm_fb_cma_helper.c:46: undefined reference to `drm_gem_fb_get_obj'

Hi!

Am 27.10.21 um 08:50 schrieb Arnd Bergmann:

On Wed, Oct 27, 2021 at 8:26 AM Randy Dunlap [off-list ref] wrote:

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On 10/26/21 11:19 PM, Arnd Bergmann wrote:

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On Wed, Oct 27, 2021 at 2:58 AM Randy Dunlap [off-list ref] wrote:

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This trivial change makes it all build:

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index c08860db2520..699f434ce813 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig

@@ -218,7 +218,7 @@ config DRM_GEM_CMA_HELPER
            Choose this if you need the GEM CMA helper functions

   config

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-       bool
+       tristate
          depends on DRM
          select DRM_GEM_CMA_HELPER
          help

but this needs some more testing to make sure it doesn't add
any other regressions.

Interestingly, I never hit the problem in randconfig testing since
there is always some '=y' driver that selects DRM_KMS_HELPER.

Thomas had posted a patch that also fixes the problem.
Somehow I missed seeing that the first time around.

Ah right, I missed that as well. That patch seems reasonable
to me, but I think we may want both of them in this case, as
it does not address DRM_GEM_CMA_HELPER being set to =y
when it is only used from modules.

Yes, the bool state was indeed the problem. The patch I posted resolves 
the issue for now. For later, I have a patchset that improves CMA helper 
usage a bit and resolves the Kconfig problem.

Best regards
Thomas

        Arnd

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
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