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

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Message-ID: <2b3d3295278c47b8a79c9ff9b10cc7de@ite.com.tw>
Date: Thu, 26 Sep 2024 09:46:42 +0000
From: <Hermes.Wu@....com.tw>
To: <dmitry.baryshkov@...aro.org>
CC: <Kenneth.Hung@....com.tw>, <andrzej.hajda@...el.com>,
        <neil.armstrong@...aro.org>, <rfoss@...nel.org>,
        <Laurent.pinchart@...asonboard.com>, <jonas@...boo.se>,
        <jernej.skrabec@...il.com>, <maarten.lankhorst@...ux.intel.com>,
        <mripard@...nel.org>, <tzimmermann@...e.de>, <airlied@...il.com>,
        <simona@...ll.ch>, <angelogioacchino.delregno@...labora.com>,
        <dri-devel@...ts.freedesktop.org>, <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.

It will be a necessary change for HDCP reads KSV FIFO.


>
>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
>

BR,
Hermes