The IT6505 is using functions provided by the DRM_DP_HELPER driver.
In order to avoid having the bridge enabled but the helper disabled,
let's add a select in order to be sure that the DP helper functions are
always available.

Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
Signed-off-by: Fabien Parent <fparent@baylibre.com>
---
 drivers/gpu/drm/bridge/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 007e5a282f67..2145b08f9534 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -78,6 +78,7 @@ config DRM_ITE_IT6505
         tristate "ITE IT6505 DisplayPort bridge"
         depends on OF
         select DRM_KMS_HELPER
+        select DRM_DP_HELPER
         select EXTCON
         help
           ITE IT6505 DisplayPort bridge chip driver.
-- 
2.36.0

Hi,

On Tue, 26 Apr 2022 16:15:36 +0200, Fabien Parent wrote:
> The IT6505 is using functions provided by the DRM_DP_HELPER driver.
> In order to avoid having the bridge enabled but the helper disabled,
> let's add a select in order to be sure that the DP helper functions are
> always available.
> 
> 

Thanks, Applied to https://anongit.freedesktop.org/git/drm/drm-misc.git (drm-misc-fixes)

[1/1] drm/bridge: ite-it6505: add missing Kconfig option select
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=841e512ffb64898db6322c0619f6bbc41266d86f

-- 
Neil

On 26/04/2022 16:15, Fabien Parent wrote:
> The IT6505 is using functions provided by the DRM_DP_HELPER driver.
> In order to avoid having the bridge enabled but the helper disabled,
> let's add a select in order to be sure that the DP helper functions are
> always available.
> 
> Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
> Signed-off-by: Fabien Parent <fparent@baylibre.com>
> ---
>   drivers/gpu/drm/bridge/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 007e5a282f67..2145b08f9534 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -78,6 +78,7 @@ config DRM_ITE_IT6505
>           tristate "ITE IT6505 DisplayPort bridge"
>           depends on OF
>           select DRM_KMS_HELPER
> +        select DRM_DP_HELPER
>           select EXTCON
>           help
>             ITE IT6505 DisplayPort bridge chip driver.

http://lore.kernel.org/r/20220403151637.15546-1-rdunlap@infradead.org also select DRM_DP_AUX_BUS,
can you check if this is really neaded ?

Neil

On Tue, Apr 26, 2022 at 05:29:31PM +0200, Neil Armstrong wrote:
> On 26/04/2022 16:15, Fabien Parent wrote:
> > The IT6505 is using functions provided by the DRM_DP_HELPER driver.
> > In order to avoid having the bridge enabled but the helper disabled,
> > let's add a select in order to be sure that the DP helper functions are
> > always available.
> > 
> > Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
> > Signed-off-by: Fabien Parent <fparent@baylibre.com>
> > ---
> >   drivers/gpu/drm/bridge/Kconfig | 1 +
> >   1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> > index 007e5a282f67..2145b08f9534 100644
> > --- a/drivers/gpu/drm/bridge/Kconfig
> > +++ b/drivers/gpu/drm/bridge/Kconfig
> > @@ -78,6 +78,7 @@ config DRM_ITE_IT6505
> >           tristate "ITE IT6505 DisplayPort bridge"
> >           depends on OF
> >           select DRM_KMS_HELPER
> > +        select DRM_DP_HELPER
> >           select EXTCON
> >           help
> >             ITE IT6505 DisplayPort bridge chip driver.
> 
> http://lore.kernel.org/r/20220403151637.15546-1-rdunlap@infradead.org also select DRM_DP_AUX_BUS,
> can you check if this is really neaded ?

Oops, I didn't notice that patch.

Anyway I can successfully link with the following config:
CONFIG_DRM_ITE_IT6505=y
CONFIG_DRM_DP_AUX_BUS=m
CONFIG_DRM_DP_HELPER=y

But I cannot with the following config:
CONFIG_DRM_ITE_IT6505=y
CONFIG_DRM_DP_AUX_BUS=m
CONFIG_DRM_DP_HELPER=m

This suggest that DRM_DP_AUX_BUS is not required for that driver.

Fabien

> 
> Neil

Hi,

On 26/04/2022 17:39, Fabien Parent wrote:
> On Tue, Apr 26, 2022 at 05:29:31PM +0200, Neil Armstrong wrote:
>> On 26/04/2022 16:15, Fabien Parent wrote:
>>> The IT6505 is using functions provided by the DRM_DP_HELPER driver.
>>> In order to avoid having the bridge enabled but the helper disabled,
>>> let's add a select in order to be sure that the DP helper functions are
>>> always available.
>>>
>>> Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
>>> Signed-off-by: Fabien Parent <fparent@baylibre.com>
>>> ---
>>>    drivers/gpu/drm/bridge/Kconfig | 1 +
>>>    1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>>> index 007e5a282f67..2145b08f9534 100644
>>> --- a/drivers/gpu/drm/bridge/Kconfig
>>> +++ b/drivers/gpu/drm/bridge/Kconfig
>>> @@ -78,6 +78,7 @@ config DRM_ITE_IT6505
>>>            tristate "ITE IT6505 DisplayPort bridge"
>>>            depends on OF
>>>            select DRM_KMS_HELPER
>>> +        select DRM_DP_HELPER
>>>            select EXTCON
>>>            help
>>>              ITE IT6505 DisplayPort bridge chip driver.
>>
>> http://lore.kernel.org/r/20220403151637.15546-1-rdunlap@infradead.org also select DRM_DP_AUX_BUS,
>> can you check if this is really neaded ?
> 
> Oops, I didn't notice that patch.
> 
> Anyway I can successfully link with the following config:
> CONFIG_DRM_ITE_IT6505=y
> CONFIG_DRM_DP_AUX_BUS=m
> CONFIG_DRM_DP_HELPER=y
> 
> But I cannot with the following config:
> CONFIG_DRM_ITE_IT6505=y
> CONFIG_DRM_DP_AUX_BUS=m
> CONFIG_DRM_DP_HELPER=m
> 
> This suggest that DRM_DP_AUX_BUS is not required for that driver.

Thanks for confirming:
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>

> 
> Fabien
> 
>>
>> Neil