Re: [PATCH v7 3/6] mfd: cros-ec: Increase maximum mkbp event size

[Neil Armstrong <narmstrong@baylibre.com>]

Hi Lee,

On 03/07/2018 11:43, Lee Jones wrote:
> On Mon, 18 Jun 2018, Neil Armstrong wrote:
> 
>> Hi Lee,
>>
>> On 18/06/2018 09:44, Lee Jones wrote:
>>> On Fri, 01 Jun 2018, Neil Armstrong wrote:
>>>
>>>> Having a 16 byte mkbp event size makes it possible to send CEC
>>>> messages from the EC to the AP directly inside the mkbp event
>>>> instead of first doing a notification and then a read.
>>>>
>>>> Signed-off-by: Stefan Adolfsson <sadolfsson@chromium.org>
>>>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>>>> Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>>>> ---
>>>>  drivers/platform/chrome/cros_ec_proto.c | 40 +++++++++++++++++++++++++--------
>>>>  include/linux/mfd/cros_ec.h             |  2 +-
>>>>  include/linux/mfd/cros_ec_commands.h    | 19 ++++++++++++++++
>>>>  3 files changed, 51 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
>>>> index e7bbdf9..c4f6c44 100644
>>>> --- a/drivers/platform/chrome/cros_ec_proto.c
>>>> +++ b/drivers/platform/chrome/cros_ec_proto.c
>>>> @@ -504,10 +504,31 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
>>>>  }
>>>>  EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
>>>>  
>>>> +static int get_next_event_xfer(struct cros_ec_device *ec_dev,
>>>> +			       struct cros_ec_command *msg,
>>>> +			       int version, uint32_t size)
>>>> +{
>>>> +	int ret;
>>>> +
>>>> +	msg->version = version;
>>>> +	msg->command = EC_CMD_GET_NEXT_EVENT;
>>>> +	msg->insize = size;
>>>> +	msg->outsize = 0;
>>>> +
>>>> +	ret = cros_ec_cmd_xfer(ec_dev, msg);
>>>> +	if (ret > 0) {
>>>> +		ec_dev->event_size = ret - 1;
>>>> +		memcpy(&ec_dev->event_data, msg->data, ec_dev->event_size);
>>>> +	}
>>>> +
>>>> +	return ret;
>>>> +}
>>>> +
>>>>  static int get_next_event(struct cros_ec_device *ec_dev)
>>>>  {
>>>>  	u8 buffer[sizeof(struct cros_ec_command) + sizeof(ec_dev->event_data)];
>>>>  	struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
>>>> +	static int cmd_version = 1;
>>>>  	int ret;
>>>>  
>>>>  	if (ec_dev->suspended) {
>>>> @@ -515,18 +536,19 @@ static int get_next_event(struct cros_ec_device *ec_dev)
>>>>  		return -EHOSTDOWN;
>>>>  	}
>>>>  
>>>> -	msg->version = 0;
>>>> -	msg->command = EC_CMD_GET_NEXT_EVENT;
>>>> -	msg->insize = sizeof(ec_dev->event_data);
>>>> -	msg->outsize = 0;
>>>> +	if (cmd_version == 1) {
>>>> +		ret = get_next_event_xfer(ec_dev, msg, cmd_version,
>>>> +				sizeof(struct ec_response_get_next_event_v1));
>>>> +		if (ret < 0 || msg->result != EC_RES_INVALID_VERSION)
>>>> +			return ret;
>>>>  
>>>> -	ret = cros_ec_cmd_xfer(ec_dev, msg);
>>>> -	if (ret > 0) {
>>>> -		ec_dev->event_size = ret - 1;
>>>> -		memcpy(&ec_dev->event_data, msg->data,
>>>> -		       sizeof(ec_dev->event_data));
>>>> +		/* Fallback to version 0 for future send attempts */
>>>> +		cmd_version = 0;
>>>>  	}
>>>>  
>>>> +	ret = get_next_event_xfer(ec_dev, msg, cmd_version,
>>>> +				  sizeof(struct ec_response_get_next_event));
>>>> +
>>>>  	return ret;
>>>>  }
>>>>  
>>>> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
>>>> index f36125e..32caef3 100644
>>>> --- a/include/linux/mfd/cros_ec.h
>>>> +++ b/include/linux/mfd/cros_ec.h
>>>> @@ -147,7 +147,7 @@ struct cros_ec_device {
>>>>  	bool mkbp_event_supported;
>>>>  	struct blocking_notifier_head event_notifier;
>>>>  
>>>> -	struct ec_response_get_next_event event_data;
>>>> +	struct ec_response_get_next_event_v1 event_data;
>>>>  	int event_size;
>>>>  	u32 host_event_wake_mask;
>>>>  };
>>>> diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
>>>> index f2edd99..cc0768e 100644
>>>> --- a/include/linux/mfd/cros_ec_commands.h
>>>> +++ b/include/linux/mfd/cros_ec_commands.h
>>>> @@ -2093,12 +2093,31 @@ union ec_response_get_next_data {
>>>>  	uint32_t   sysrq;
>>>>  } __packed;
>>>>  
>>>> +union ec_response_get_next_data_v1 {
>>>> +	uint8_t   key_matrix[16];
>>>> +
>>>> +	/* Unaligned */
>>>
>>> That's funny!
>>>
>>>> +	uint32_t  host_event;
>>>> +
>>>> +	uint32_t   buttons;
>>>> +	uint32_t   switches;
>>>> +	uint32_t   sysrq;
>>>> +	uint32_t   cec_events;
>>>> +	uint8_t    cec_message[16];
>>>
>>> Since there are some whitespace alignment issues in here.
> 
> Fix the white space issues.

Ok

> 
>>>> +} __packed;
>>>
>>> How come these guys have kerneldoc headers?
> 
> Consider using kerneldoc headers (not required for this patch).

I already used kerneldoc for the other patch as requested by Enric.

> 
>> Can you explicit what should be changed here ?
> 
> -^

Ok

Thanks,
Neil

> 
>>>>  struct ec_response_get_next_event {
>>>>  	uint8_t event_type;
>>>>  	/* Followed by event data if any */
>>>>  	union ec_response_get_next_data data;
>>>>  } __packed;
>>>>  
>>>> +struct ec_response_get_next_event_v1 {
>>>> +	uint8_t event_type;
>>>> +	/* Followed by event data if any */
>>>> +	union ec_response_get_next_data_v1 data;
>>>> +} __packed;
>>>> +
>>>>  /* Bit indices for buttons and switches.*/
>>>>  /* Buttons */
>>>>  #define EC_MKBP_POWER_BUTTON	0
>>>
>>
>