Date:   Mon, 30 Jan 2023 10:41:18 +0100
From:   Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
To:     Arnd Bergmann <arnd@kernel.org>
Cc:     Oded Gabbay <ogabbay@kernel.org>, Dave Airlie <airlied@redhat.com>,
        Melissa Wen <mwen@igalia.com>,
        Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>,
        Jeffrey Hugo <quic_jhugo@quicinc.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH] [v2] accel: fix CONFIG_DRM dependencies
Message-ID: <20230130094118.GA1627912@linux.intel.com>
References: <20230127221504.2522909-1-arnd@kernel.org>
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On Fri, Jan 27, 2023 at 11:14:55PM +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'
> 
> The problem is that DRM_ACCEL is a 'bool' symbol symbol, so driver that
> only depend on DRM_ACCEL but not also on DRM do not see the restriction
> to =m configs.
> 
> To ensure that each accel driver has an implied dependency on CONFIG_DRM,
> enclose the entire Kconfig file in an if/endif check.
> 
> Fixes: 8bf4889762a8 ("drivers/accel: define kconfig and register a new major")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

> ---
> v2: rearrage the DRM dependency rather than requiring DRM to be built-in
> ---
>  drivers/accel/Kconfig | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig
> index 834863902e16..c437206aa3f1 100644
> --- a/drivers/accel/Kconfig
> +++ b/drivers/accel/Kconfig
> @@ -6,9 +6,10 @@
>  # as, but not limited to, Machine-Learning and Deep-Learning acceleration
>  # devices
>  #
> +if DRM
> +
>  menuconfig DRM_ACCEL
>  	bool "Compute Acceleration Framework"
> -	depends on DRM
>  	help
>  	  Framework for device drivers of compute acceleration devices, such
>  	  as, but not limited to, Machine-Learning and Deep-Learning
> @@ -25,3 +26,5 @@ menuconfig DRM_ACCEL
>  
>  source "drivers/accel/habanalabs/Kconfig"
>  source "drivers/accel/ivpu/Kconfig"
> +
> +endif
> -- 
> 2.39.0
>