[PATCH] drm/amd/display: Fix HW/SW state mismatch

[Harry Wentland]

On 2020-01-16 3:20 p.m., Bhawanpreet Lakha wrote:
> [Why]
> When we disable a connector we don't explicitly remove it from the module so the
> display is still cached(SW) in the hdcp_module.
> 
> SST: no issues because we can only have 1 display per link
> 
> MST: We have x displays per link, now if we disable 1 we don't remove it from the
> module so the module has x display cached(SW).
> 
> If we try to enable HDCP, psp verification will fail because we are reporting x
> displays while the HW only has x-1 display enabled
> 
> [How]
> Check the callback for when we disable stream and call remove display.
> 
> Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
> Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>

Acked-by: Harry Wentland <harry.wentland at amd.com>

Harry

> ---
>  .../amd/display/amdgpu_dm/amdgpu_dm_hdcp.c    | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c
> index ae329335dfcc..0acd3409dd6c 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c
> @@ -135,6 +135,20 @@ void hdcp_update_display(struct hdcp_workqueue *hdcp_work,
>  	mutex_unlock(&hdcp_w->mutex);
>  }
>  
> +static void hdcp_remove_display(struct hdcp_workqueue *hdcp_work,
> +			 unsigned int link_index,
> +			 struct amdgpu_dm_connector *aconnector)
> +{
> +	struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
> +
> +	mutex_lock(&hdcp_w->mutex);
> +	hdcp_w->aconnector = aconnector;
> +
> +	mod_hdcp_remove_display(&hdcp_w->hdcp, aconnector->base.index, &hdcp_w->output);
> +
> +	process_output(hdcp_w);
> +	mutex_unlock(&hdcp_w->mutex);
> +}
>  void hdcp_reset_display(struct hdcp_workqueue *hdcp_work, unsigned int link_index)
>  {
>  	struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];
> @@ -303,6 +317,11 @@ static void update_config(void *handle, struct cp_psp_stream_config *config)
>  	memset(link, 0, sizeof(*link));
>  
>  	display->index = aconnector->base.index;
> +
> +	if (config->dpms_off) {
> +		hdcp_remove_display(hdcp_work, link_index, aconnector);
> +		return;
> +	}
>  	display->state = MOD_HDCP_DISPLAY_ACTIVE;
>  
>  	if (aconnector->dc_sink != NULL)
>