linux-kernel - Re: [PATCH v4 10/11] drm/bridge: it6505: fix HDCP CTS ksv wait timer

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Message-ID: <7pazkukfrskc6o2zd23h6o4wyt7ougjjgnmogy2effr2lof7di@7opphoswhebf>
Date: Thu, 26 Sep 2024 11:20:39 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Hermes Wu <Hermes.Wu@....com.tw>
Cc: Kenneth Hung <Kenneth.hung@....com.tw>, 
	Andrzej Hajda <andrzej.hajda@...el.com>, Neil Armstrong <neil.armstrong@...aro.org>, 
	Robert Foss <rfoss@...nel.org>, Laurent Pinchart <Laurent.pinchart@...asonboard.com>, 
	Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, 
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>, Allen Chen <allen.chen@....com.tw>, 
	"open list:DRM DRIVERS" <dri-devel@...ts.freedesktop.org>, open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 10/11] drm/bridge: it6505: fix HDCP CTS ksv wait timer

On Thu, Sep 26, 2024 at 03:51:33PM GMT, Hermes Wu wrote:
> From: Hermes Wu <Hermes.wu@....com.tw>
> 
> When running the HDCP CTS test on UNIGRAF DPR-100.
> HDCP must disabled after waiting KSV for 5s.
> Consider system ksv work schedules. The original timer has a chance to expire.

I can't understand two last sentences, excuse me.

Nit: KSV, not ksv

> 
> Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
> Signed-off-by: Hermes Wu <Hermes.wu@....com.tw>
> ---
>  drivers/gpu/drm/bridge/ite-it6505.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
> index e75bc1575aa8..22d9bec3faea 100644
> --- a/drivers/gpu/drm/bridge/ite-it6505.c
> +++ b/drivers/gpu/drm/bridge/ite-it6505.c
> @@ -2093,7 +2093,8 @@ static void it6505_hdcp_wait_ksv_list(struct work_struct *work)
>  	struct it6505 *it6505 = container_of(work, struct it6505,
>  					     hdcp_wait_ksv_list);
>  	struct device *dev = it6505->dev;
> -	unsigned int timeout = 5000;
> +	/* 1B-04 fail, wait to long to Stop encription(5s->3s). */

encryption, most likely it's also "too long".

> +	unsigned int timeout = 3000;

What is the timeout per the standard?

>  	u8 bstatus = 0;
>  	bool ksv_list_check;
>  
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry