Re: [PATCH] soc: qcom: pmic_glink: fix connector type to be DisplayPort

[Dmitry Baryshkov]

On 25/10/2023 15:23, Johan Hovold wrote:
> On Wed, Oct 11, 2023 at 01:52:29AM +0300, Dmitry Baryshkov wrote:
> > As it was pointed out by Simon Ser, the DRM_MODE_CONNECTOR_USB connector
> > is reserved for the GUD devices. Other drivers (i915, amdgpu) use
> > DRM_MODE_CONNECTOR_DisplayPort even if the DP stream is handled by the
> > USB-C altmode. While we are still working on implementing the proper way
> > to let userspace know that the DP is wrapped into USB-C, change
> > connector type to be DRM_MODE_CONNECTOR_DisplayPort.
> >
> > Fixes: 080b4e24852b ("soc: qcom: pmic_glink: Introduce altmode support")
> > Cc: Simon Ser <contact@xxxxxxxxxxx>
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > ---
> >   drivers/soc/qcom/pmic_glink_altmode.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/soc/qcom/pmic_glink_altmode.c b/drivers/soc/qcom/pmic_glink_altmode.c
> > index 9569d999391d..6f8b2f7ae3cc 100644
> > --- a/drivers/soc/qcom/pmic_glink_altmode.c
> > +++ b/drivers/soc/qcom/pmic_glink_altmode.c
> > @@ -467,7 +467,7 @@ static int pmic_glink_altmode_probe(struct auxiliary_device *adev,
> >   		alt_port->bridge.funcs = &pmic_glink_altmode_bridge_funcs;
> >   		alt_port->bridge.of_node = to_of_node(fwnode);
> >   		alt_port->bridge.ops = DRM_BRIDGE_OP_HPD;
> > -		alt_port->bridge.type = DRM_MODE_CONNECTOR_USB;
> > +		alt_port->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
> >   
> >   		ret = devm_drm_bridge_add(dev, &alt_port->bridge);
> >   		if (ret) {
>
> I was just going to post a patch fixing this after finally investigating
> why the DisplayPort outputs on the X13s were annoyingly identified as
> "Unknown20-1" and "Unknown20-2" instead of the expected "DP-1" and
> "DP-2".

Well, that depends on the userspace being updated to know about USB 
connectors or not. But you are right, we should probably mention that in 
the commit message.

> A lore search just before posting led me to this fix from two weeks ago.
>
> I think the commit message should have mentioned something about the how
> this change affects user space. My patch also had a CC stable, but I
> guess we can ping the stable team once it hits mainline:
>
> commit e5f55bf5ad4effdd59d4d06c839a0ac553a73c7d (HEAD -> work)
> Author: Johan Hovold <johan+linaro@xxxxxxxxxx>
> Date:   Wed Oct 25 11:54:09 2023 +0200
>
>      soc: qcom: pmic_glink_altmode: fix DP alt mode connector type
>      
>      The PMIC glink altmode bridge connector type should be "DisplayPort"
>      rather than "USB", which is intended for custom USB display protocols
>      (e.g. see 40e1a70b4aed ("drm: Add GUD USB Display driver")).
>      
>      This specifically makes the DisplayPort outputs on the Lenovo ThinkPad
>      X13s show up as "DP-1" and "DP-2" rather than "Unknown20-1" and
>      "Unknown20-2" with xrandr as expected (by users and tools):
>      
>        Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 5120 x 4096
>        eDP-1 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 286mm x 178mm
>           1920x1200     60.03*+
>           1600x1200     60.00
>        DP-1 disconnected (normal left inverted right x axis y axis)
>        DP-2 connected (normal left inverted right x axis y axis)
>           1920x1200     59.95 +
>        ...
>      
>      Fixes: 080b4e24852b ("soc: qcom: pmic_glink: Introduce altmode support")
>      Cc: stable@xxxxxxxxxxxxxxx      # 6.3
>      Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
>
> Johan

--
With best wishes
Dmitry