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Message-ID: <5a01bedd-9150-b23c-7e2a-08d2e7da0fe6@redhat.com>
Date:   Wed, 27 Oct 2021 14:56:28 +0200
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Subject: Re: [PATCH] [RESEND] drm: fb_helper: fix CONFIG_FB dependency
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To:     Arnd Bergmann <arnd@kernel.org>
Cc:     Jani Nikula <jani.nikula@linux.intel.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Kees Cook <keescook@chromium.org>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@linux.ie>, Arnd Bergmann <arnd@arndb.de>,
        Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <20210927142816.2069269-1-arnd@kernel.org>
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From:   Javier Martinez Canillas <javierm@redhat.com>
In-Reply-To: <CAK8P3a0_9U0MDLcNG8GL_ZDCGQAsB=G7DBC0k1BYB1HNQTbu4Q@mail.gmail.com>
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On 10/27/21 14:52, Arnd Bergmann wrote:

[snip]

>>
>> @@ -104,7 +105,6 @@ config DRM_FBDEV_EMULATION
>>         bool "Enable legacy fbdev support for your modesetting driver"
>>         depends on DRM
>>         depends on FB
>> -       select DRM_KMS_HELPER
>>         select FB_CFB_FILLRECT
>>         select FB_CFB_COPYAREA
>>         select FB_CFB_IMAGEBLIT
> 
> This fails because of all the other drivers that try to 'select DRM_KMS_HELPER'.
> Kconfig will now complain about a symbol that gets selected while its
> dependencies
> are not met.
> 
> To work around that, every single driver that has 'selects DRM_KMS_HELPER' would
> now have to also list 'depends on (DRM_FBDEV_EMULATION && FB) ||
> !DRM_FBDEV_EMULATION'.
>

Ah, I see now. Thanks a lot for the explanation.
 
>        Arnd
> 

Best regards,
-- 
Javier Martinez Canillas
Linux Engineering
Red Hat