Re: [PATCH v3] usb: typec: altmodes: select DRM_AUX_HPD_BRIDGE for TYPEC_DP_ALTMODE

[Heikki Krogerus]

On Thu, Jul 16, 2026 at 06:31:45PM +0800, Chaoyi Chen wrote:
> On 7/16/2026 4:44 PM, Heikki Krogerus wrote:
> > On Wed, Jul 15, 2026 at 09:19:24AM +0800, Chaoyi Chen wrote:
> >> Hi Heikki,
> >>
> >> On 7/13/2026 5:35 PM, Heikki Krogerus wrote:
> >>> On Thu, Jul 09, 2026 at 02:21:47PM +0800, Chaoyi Chen wrote:
> >>>> From: Chaoyi Chen <chaoyi.chen@xxxxxxxxxxxxxx>
> >>>>
> >>>> When TYPEC_DP_ALTMODE is enabled, DRM_AUX_HPD_BRIDGE is most likely
> >>>> also needed for embedded platforms. Select it when available.
> >>>>
> >>>> Suggested-by: Xu Yang <xu.yang_2@xxxxxxxxxxx>
> >>>> Signed-off-by: Chaoyi Chen <chaoyi.chen@xxxxxxxxxxxxxx>
> >>>> ---
> >>>> Changes in v3:
> >>>> - Link to v2: https://lore.kernel.org/all/20260705065832.184-1-kernel@xxxxxxxxxx/
> >>>> - Use the same "select" as v1 to make things simple. 
> >>>>
> >>>> Changes in v2:
> >>>> - Link to v1: https://lore.kernel.org/all/20260702022036.44-1-kernel@xxxxxxxxxx/
> >>>> - Change "select" to "imply".
> >>>> ---
> >>>>
> >>>>  drivers/usb/typec/altmodes/Kconfig | 1 +
> >>>>  1 file changed, 1 insertion(+)
> >>>>
> >>>> diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
> >>>> index 7867fa7c405d..b054c0b6a8d4 100644
> >>>> --- a/drivers/usb/typec/altmodes/Kconfig
> >>>> +++ b/drivers/usb/typec/altmodes/Kconfig
> >>>> @@ -5,6 +5,7 @@ menu "USB Type-C Alternate Mode drivers"
> >>>>  config TYPEC_DP_ALTMODE
> >>>>  	tristate "DisplayPort Alternate Mode driver"
> >>>>  	depends on DRM
> >>>> +	select DRM_AUX_HPD_BRIDGE if DRM_BRIDGE && OF
> >>>
> >>> Is there really no way of making this into a dependency?
> >>> Doesn't this, or something like it not work:
> >>>
> >>>         depends on (DRM_AUX_HPD_BRIDGE && DRM_BRIDGE && OF) || !DRM_AUX_HPD_BRIDGE
> >>>
> >>
> >> I think Xu originally wanted to select this item directly, since it
> >> wasn't visible in the menu and there was nowhere to select it on some platforms.
> > 
> > But now it is user selectable, no?
> 
> No, currently it needs to be explicitly selected in Kconfig, 
> and it is not visible to the user.

Okay, yet another Kconfig option with dependencies that's not user
selectable. Meaning, everything that selects that option has to carry
the same dependencies, and hope that if those dependencies ever change
they are updated everywhere. :(

I still don't like this at all, but let's go with it for now.

Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

Thanks,

-- 
heikki