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Message-ID: <13ca5824-c101-823a-b31e-ccf9a6971c20@baylibre.com>
Date:   Tue, 26 Apr 2022 17:59:01 +0200
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Subject: Re: [PATCH] drm/bridge: ite-it6505: add missing Kconfig option select
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To:     Fabien Parent <fparent@baylibre.com>
Cc:     Andrzej Hajda <andrzej.hajda@intel.com>,
        Robert Foss <robert.foss@linaro.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Hermes Wu <hermes.wu@ite.com.tw>,
        Allen Chen <allen.chen@ite.com.tw>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <20220426141536.274727-1-fparent@baylibre.com>
 <fd02a183-bcaa-86a8-8a13-52a9ddb374d5@baylibre.com>
 <20220426153931.suiuc7o53dt6s2es@radium>
From:   Neil Armstrong <narmstrong@baylibre.com>
Organization: Baylibre
In-Reply-To: <20220426153931.suiuc7o53dt6s2es@radium>
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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