linux-kernel - Re: [PATCH v4 03/11] drm/bridge: it6505: add aux operation for HDCP ksv list read

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Message-ID: <acpumgqlyjyt5ql2imnhrv32apdjzluahnx77xpqu2lzltko4q@j6fhqrb7sxai>
Date: Thu, 26 Sep 2024 10:57:51 +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>, Allen Chen <allen.chen@....com.tw>, 
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>, "open list:DRM DRIVERS" <dri-devel@...ts.freedesktop.org>, 
	open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 03/11] drm/bridge: it6505: add aux operation for HDCP
 ksv list read

On Thu, Sep 26, 2024 at 03:47:53PM GMT, Hermes Wu wrote:
> From: Hermes Wu <Hermes.wu@....com.tw>
> 
> Add aux operaction command which supports read DPCD KSV FIFO
> with aux fifo.

Nit: AUX, FIFO. Please be consistent in your commit messages.

> 
> 
> Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")

Why is this considered to be a fix? From the commit message it sounds
like a new feature.

LGTM otherwise

> Signed-off-by: Hermes Wu <Hermes.wu@....com.tw>
> ---
>  drivers/gpu/drm/bridge/ite-it6505.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
> index b451d3c2ac1d..0583abdca75f 100644
> --- a/drivers/gpu/drm/bridge/ite-it6505.c
> +++ b/drivers/gpu/drm/bridge/ite-it6505.c
> @@ -324,6 +324,9 @@ enum aux_cmd_type {
>  	CMD_AUX_NATIVE_READ = 0x0,
>  	CMD_AUX_NATIVE_WRITE = 0x5,
>  	CMD_AUX_I2C_EDID_READ = 0xB,
> +
> +	/* KSV list read using AUX native read with FIFO */
> +	CMD_AUX_GET_KSV_LIST = 0x10,
>  };
>  
>  enum aux_cmd_reply {
> @@ -965,7 +968,8 @@ static ssize_t it6505_aux_operation(struct it6505 *it6505,
>  	it6505_set_bits(it6505, REG_AUX_CTRL, AUX_USER_MODE, AUX_USER_MODE);
>  
>  aux_op_start:
> -	if (cmd == CMD_AUX_I2C_EDID_READ) {
> +	/* HW AUX FIFO supports only EDID and DCPD KSV FIFO aread */
> +	if (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST) {
>  		/* AUX EDID FIFO has max length of AUX_FIFO_MAX_SIZE bytes. */
>  		size = min_t(size_t, size, AUX_FIFO_MAX_SIZE);
>  		/* Enable AUX FIFO read back and clear FIFO */
> @@ -1030,7 +1034,7 @@ static ssize_t it6505_aux_operation(struct it6505 *it6505,
>  		goto aux_op_start;
>  	}
>  
> -	if (cmd == CMD_AUX_I2C_EDID_READ) {
> +	if (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST) {
>  		for (i = 0; i < size; i++) {
>  			ret = it6505_read(it6505, REG_AUX_DATA_FIFO);
>  			if (ret < 0)
> @@ -1055,7 +1059,7 @@ static ssize_t it6505_aux_operation(struct it6505 *it6505,
>  	ret = i;
>  
>  aux_op_err:
> -	if (cmd == CMD_AUX_I2C_EDID_READ) {
> +	if (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST) {
>  		/* clear AUX FIFO */
>  		it6505_set_bits(it6505, REG_AUX_CTRL,
>  				AUX_EN_FIFO_READ | CLR_EDID_FIFO,
> @@ -1079,7 +1083,7 @@ static ssize_t it6505_aux_do_transfer(struct it6505 *it6505,
>  
>  	mutex_lock(&it6505->aux_lock);
>  	for (i = 0; i < size; ) {
> -		if (cmd == CMD_AUX_I2C_EDID_READ)
> +		if (cmd == CMD_AUX_I2C_EDID_READ || cmd == CMD_AUX_GET_KSV_LIST)
>  			request_size = min_t(int, (int)size - i, AUX_FIFO_MAX_SIZE);
>  		else
>  			request_size = min_t(int, (int)size - i, 4);
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry