linux-kernel - Re: [PATCH v2 2/3] Subject: [PATCH] drm/mediatek/dp: Add HDCP2.x feature for DisplayPort

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Date: Tue, 20 Feb 2024 09:30:27 +0000
From: CK Hu (胡俊光) <ck.hu@...iatek.com>
To: Mac Shen (沈俊) <Mac.Shen@...iatek.com>,
	"chunkuang.hu@...nel.org" <chunkuang.hu@...nel.org>,
	Jitao Shi (石记涛) <jitao.shi@...iatek.com>,
	"daniel@...ll.ch" <daniel@...ll.ch>, "p.zabel@...gutronix.de"
	<p.zabel@...gutronix.de>, "airlied@...il.com" <airlied@...il.com>,
	"matthias.bgg@...il.com" <matthias.bgg@...il.com>,
	"angelogioacchino.delregno@...labora.com"
	<angelogioacchino.delregno@...labora.com>
CC: "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-mediatek@...ts.infradead.org" <linux-mediatek@...ts.infradead.org>,
	"linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>,
	Shuijing Li (李水静) <Shuijing.Li@...iatek.com>
Subject: Re: [PATCH v2 2/3] Subject: [PATCH] drm/mediatek/dp: Add HDCP2.x
 feature for DisplayPort

Hi, Mac:

On Mon, 2024-02-05 at 13:50 +0800, mac.shen wrote:
> Add HDCP2.x feature for DisplayPort.
> When userspace request the kernel protect future content communicated
> over the link with Content_Protection property, the feature will do
> HDCP2.x authentication if the sink support HDCP2.X.
> 
> Changes in v2:
> - remove switch case, and refine code to make more clear
> - remove some definitions, and use the definitions in
>   include/drm/drm_hdcp.h
> - use the struct which defined in include/drm/drm_hdcp.h
> - do HDCP2.x authentication when userspace request the
>   kernel protect future content communicated
> per suggestion from the previous thread:
> https://lore.kernel.org/all/8fff59b5567449d8201dd1138c8fa
> 9218a545c46.camel@...iatek.com/
> 
> Signed-off-by: mac.shen <mac.shen@...iatek.com>
> ---

[snip]

>  
> +void mtk_dp_check_hdcp_version(struct mtk_dp *mtk_dp, bool
> only_hdcp1x)
> +{
> +	if (!only_hdcp1x && dp_tx_hdcp2_support(&mtk_dp->hdcp_info))
> +		return;
> +
> +	if (tee_add_device(&mtk_dp->hdcp_info, HDCP_NONE) !=
> RET_SUCCESS)

Does this mean that if rx does not support hdcp, dp tx driver still
need to create tee device to work for no hdcp? If so, I think this
should be separated to an independent patch. I like the patch sequence
to be:

1. Support NO HDCP
2. Support HDCP 1x
3. Support HDCP 2x

Regards,
CK

> +		mtk_dp->hdcp_info.auth_status = AUTH_FAIL;
> +}
> +