[PATCH] drm/fb: Fix randconfig builds

[Jackie Liu]

Hi Jani.

My CI report an randconfigs build failed. there are:

drm_fb_helper.c:(.text+0x302): undefined reference to `fb_set_suspend'
drm_fb_helper.c:(.text+0xaea): undefined reference to `register_framebuffer'
drm_fb_helper.c:(.text+0x1dcc): undefined reference to `framebuffer_alloc'
ld: drm_fb_helper.c:(.text+0x1dea): undefined reference to `fb_alloc_cmap'
ld: drm_fb_helper.c:(.text+0x1e2f): undefined reference to `fb_dealloc_cmap'
ld: drm_fb_helper.c:(.text+0x1e5b): undefined reference to 
`framebuffer_release'
drm_fb_helper.c:(.text+0x1e85): undefined reference to 
`unregister_framebuffer'
drm_fb_helper.c:(.text+0x1ee9): undefined reference to `fb_dealloc_cmap'
ld: drm_fb_helper.c:(.text+0x1ef0): undefined reference to 
`framebuffer_release'
drm_fb_helper.c:(.text+0x1f96): undefined reference to 
`fb_deferred_io_cleanup'
drm_fb_helper.c:(.text+0x203b): undefined reference to `fb_sys_read'
drm_fb_helper.c:(.text+0x2051): undefined reference to `fb_sys_write'
drm_fb_helper.c:(.text+0x208d): undefined reference to `sys_fillrect'
drm_fb_helper.c:(.text+0x20bb): undefined reference to `sys_copyarea'
drm_fb_helper.c:(.text+0x20e9): undefined reference to `sys_imageblit'
drm_fb_helper.c:(.text+0x2117): undefined reference to `cfb_fillrect'
drm_fb_helper.c:(.text+0x2172): undefined reference to `cfb_copyarea'
drm_fb_helper.c:(.text+0x21cd): undefined reference to `cfb_imageblit'
drm_fb_helper.c:(.text+0x2233): undefined reference to `fb_set_suspend'
drm_fb_helper.c:(.text+0x22b0): undefined reference to `fb_set_suspend'
drm_fb_helper.c:(.text+0x250f): undefined reference to `fb_deferred_io_init'

The main reason is because DRM_FBDEV_EMULATION is built-in, and
CONFIG_FB is compiled as a module.

--
Jackie Liu

在 2021/8/16 下午3:01, Jani Nikula 写道:
> On Mon, 16 Aug 2021, Jackie Liu <liu.yun at linux.dev> wrote:
>> From: Jackie Liu <liuyun01 at kylinos.cn>
>>
>> When CONFIG_DRM_FBDEV_EMULATION is compiled to y and CONFIG_FB is m, the
>> compilation will fail. we need make that dependency explicit.
> 
> What's the failure mode? Using select here is a bad idea.
> 
> BR,
> Jani.
> 
>>
>> Reported-by: k2ci <kernel-bot at kylinos.cn>
>> Signed-off-by: Jackie Liu <liuyun01 at kylinos.cn>
>> ---
>>   drivers/gpu/drm/Kconfig | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>> index 7ff89690a976..346a518b5119 100644
>> --- a/drivers/gpu/drm/Kconfig
>> +++ b/drivers/gpu/drm/Kconfig
>> @@ -98,7 +98,7 @@ config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
>>   config DRM_FBDEV_EMULATION
>>   	bool "Enable legacy fbdev support for your modesetting driver"
>>   	depends on DRM
>> -	depends on FB
>> +	select FB
>>   	select DRM_KMS_HELPER
>>   	select FB_CFB_FILLRECT
>>   	select FB_CFB_COPYAREA
>