Re: [PATCH v2] platform: cros_ec: Reduce ligthbar get version command

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 25 Aug 2020 17:29:45 -0700
Gwendal Grignou <gwendal@chromium.org> wrote:

> By default, the lightbar commands are set to the
> biggest lightbar command and response. That length is greater than 128
> bytes and may not work on all machines.
> But all EC are probed for lightbar by sending a get version request.
> Set that request size precisely.
> 
> Before the command would be:
> cros_ec_cmd: version: 0, command: EC_CMD_LIGHTBAR_CMD, outsize: 194, insize: 128, result: 0
> Afer:
> cros_ec_cmd: version: 0, command: EC_CMD_LIGHTBAR_CMD, outsize: 1, insize: 8, result: 0
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Hi Gwendal,

Description seems to me to suggest this is a fix?
Are there known machines on which it doesn't work currently?

If so, please can I have a fixes tag.  If it's just a precaution
against future problems then let me know and I can add it for the
next merge window.

Thanks,

Jonathan

> ---
> Changes since v1:
> - Remove BUG and TEST fields.
> 
>  drivers/platform/chrome/cros_ec_lightbar.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
> index b59180bff5a3e..ef61298c30bdd 100644
> --- a/drivers/platform/chrome/cros_ec_lightbar.c
> +++ b/drivers/platform/chrome/cros_ec_lightbar.c
> @@ -116,6 +116,8 @@ static int get_lightbar_version(struct cros_ec_dev *ec,
>  
>  	param = (struct ec_params_lightbar *)msg->data;
>  	param->cmd = LIGHTBAR_CMD_VERSION;
> +	msg->outsize = sizeof(param->cmd);
> +	msg->result = sizeof(resp->version);
>  	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
>  	if (ret < 0) {
>  		ret = 0;