[PATCH] lontium-lt9611: check a different register bit for HDMI sensing

[Anibal Limon]

Dmitry,

May be this is the reason of my HP monitor not working in RB5.

Regards,
Anibal

El mar., 16 de noviembre de 2021 20:07, Peter Collingbourne <pcc at google.com>
escribió:

> It has been observed that with certain monitors such as the HP Z27n,
> the register 0x825e reads a value of 0x79 when the HDMI cable is
> connected and 0x78 when it is disconnected, i.e. bit 0 appears
> to correspond to the HDMI connection status and bit 2 is never
> set. Therefore, change the driver to check bit 0 instead of bit 2.
>
> Signed-off-by: Peter Collingbourne <pcc at google.com>
> Link:
> https://linux-review.googlesource.com/id/I7e76411127e1ce4988a3f6d0c8ba5f1c3d880c23
> ---
> N.B. I don't currently have easy access to a monitor that works
> with the existing driver, so it would be great if people with
> monitors that currently work could test this patch to make sure
> that it doesn't introduce any regressions. Otherwise I will change
> it to check both bits.
>
>  drivers/gpu/drm/bridge/lontium-lt9611.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c
> b/drivers/gpu/drm/bridge/lontium-lt9611.c
> index 29b1ce2140ab..71f1db802916 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9611.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
> @@ -586,7 +586,7 @@ lt9611_connector_detect(struct drm_connector
> *connector, bool force)
>         int connected = 0;
>
>         regmap_read(lt9611->regmap, 0x825e, &reg_val);
> -       connected  = (reg_val & BIT(2));
> +       connected  = (reg_val & BIT(0));
>
>         lt9611->status = connected ?  connector_status_connected :
>                                 connector_status_disconnected;
> @@ -926,7 +926,7 @@ static enum drm_connector_status
> lt9611_bridge_detect(struct drm_bridge *bridge)
>         int connected;
>
>         regmap_read(lt9611->regmap, 0x825e, &reg_val);
> -       connected  = reg_val & BIT(2);
> +       connected  = reg_val & BIT(0);
>
>         lt9611->status = connected ?  connector_status_connected :
>                                 connector_status_disconnected;
> --
> 2.34.0.rc1.387.gb447b232ab-goog
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20211116/6dee5a84/attachment-0001.htm>