On Thu, Jun 22, 2023, at 17:39, Neil Armstrong wrote:
> On 22/06/2023 13:24, Arnd Bergmann wrote:
>> On Thu, Jun 22, 2023, at 12:39, Neil Armstrong wrote:
>>>>
>>>> config TYPEC_MUX_NB7VPQ904M
>>>> tristate "On Semiconductor NB7VPQ904M Type-C redriver driver"
>>>> - depends on I2C
>>>> + depends on I2C && DRM
>>>> select REGMAP_I2C
>>>> help
>>>> Say Y or M if your system has a On Semiconductor NB7VPQ904M Type-C
>>>
>>> I think it could be :
>>>
>>> + depends on DRM || DRM=n
>>> + select DRM_PANEL_BRIDGE if DRM
>>
>> As far as I can tell, this would only avoid the link error
>> against devm_drm_of_get_bridge(), but not the one against
>> devm_drm_bridge_add(), which is defined in drm.ko through
>> drivers/gpu/drm/drm_bridge.c.
>
> I'm trying to reproduce such situation, but so fail I fail.
>
> In the driver there's a guard to avoid calling into DRM functions
> when disabled:
> #if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_DRM_PANEL_BRIDGE)
Ah, you are right. I got confused because the check is in
header file for devm_drm_of_get_bridge(), but not for
devm_drm_bridge_add(), which has the check in the source
file as you point out.
> so I wonder which kind on config leaded to that since
> CONFIG_DRM_PANEL_BRIDGE is only enabled when DRM_PANEL and DRM are.
I only saw the original issue with
CONFIG_DRM=m
CONFIG_DRM_PANEL=y
CONFIG_DRM_BRIDGE=y
CONFIG_DRM_PANEL_BRIDGE=y
CONFIG_TYPEC_MUX_NB7VPQ904M=y
and since CONFIG_DRM_PANEL_BRIDGE already depends on CONFIG_DRM,
I think that is the only one that can go wrong, so your
suggestion of
depends on DRM || DRM=n
should be sufficient. I see that DRM_PANEL, DRM_BRIDGE and
DRM_PANEL_BRIDGE are now always =y whenever DRM is enabled,
so I don't think the 'select CONFIG_DRM_PANEL_BRIDGE' serves
any purpose any more, but it's also harmless if you think it
helps for clarification.
Can you send the updated patch, or should I?
Arnd
