[PATCH] Revert "drm/amd/display: To modify the condition in indicating branch device"

[Harry Wentland]

On 2022-01-24 09:17, Alex Deucher wrote:
> This breaks HDMI audio.
> 

Do we have more info? This is DP code, but maybe the display is connected via a DP-HDMI adapter? Or via a n MST or USB-C hub?

As Siqueira mentioned, we couldn't reproduce the issue and the original change was intended to fix an issue with some receivers. Simply reverting it would likely reintroduce that bug.

Harry

> This reverts commit 9413b23fadad3861f5afd626ac44ef83ad8068ab.
> 
> Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1536
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> Cc: Martin Tsai <martin.tsai at amd.com>
> Cc: Bindu Ramamurthy <bindu.r at amd.com>
> ---
>  drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> index 6f6929435885..eb4432dca761 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> @@ -5039,7 +5039,13 @@ static void get_active_converter_info(
>  	}
>  
>  	/* DPCD 0x5 bit 0 = 1, it indicate it's branch device */
> -	link->dpcd_caps.is_branch_dev = ds_port.fields.PORT_PRESENT;
> +	if (ds_port.fields.PORT_TYPE == DOWNSTREAM_DP) {
> +		link->dpcd_caps.is_branch_dev = false;
> +	}
> +
> +	else {
> +		link->dpcd_caps.is_branch_dev = ds_port.fields.PORT_PRESENT;
> +	}
>  
>  	switch (ds_port.fields.PORT_TYPE) {
>  	case DOWNSTREAM_VGA: