Re: [PATCH 05/11] platform/chrome: cros_ec_proto: separate cros_ec_wait_until_complete()

Guenter Roeck
2022-06-15T20:50:46Z

On Tue, Jun 14, 2022 at 10:13 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> EC returns EC_RES_IN_PROGRESS if the host command needs more time to
> complete. Whenever receives the return code, cros_ec_send_command()
> sends EC_CMD_GET_COMMS_STATUS to query the command status.
>
> Separate cros_ec_wait_until_complete() from cros_ec_send_command().
> It sends EC_CMD_GET_COMMS_STATUS and waits until the previous command
> was completed, or encountered error, or timed out.
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
> ---
> drivers/platform/chrome/cros_ec_proto.c | 75 ++++++++++++-------------
> 1 file changed, 36 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 0cec013be3d3..466ecb063bd6 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -134,53 +134,50 @@ static int cros_ec_xfer_command(struct cros_ec_device *ec_dev, struct cros_ec_co
> return ret;
> }
>
> -static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
> +static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result)
> {
> - int ret = cros_ec_xfer_command(ec_dev, msg);
> + struct cros_ec_command *msg;
> + struct ec_response_get_comms_status *status;
> + int ret = 0, i;
> +
> + msg = kzalloc(sizeof(*msg) + sizeof(*status), GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
>
> - if (msg->result == EC_RES_IN_PROGRESS) {
> - int i;
> - struct cros_ec_command *status_msg;
> - struct ec_response_get_comms_status *status;
> + msg->command = EC_CMD_GET_COMMS_STATUS;
> + msg->insize = sizeof(*status);
>
> - status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
> - GFP_KERNEL);
> - if (!status_msg)
> - return -ENOMEM;
> + status = (struct ec_response_get_comms_status *)msg->data;
>
> - status_msg->version = 0;
> - status_msg->command = EC_CMD_GET_COMMS_STATUS;
> - status_msg->insize = sizeof(*status);
> - status_msg->outsize = 0;
> + /* Query the EC's status until it's no longer busy or we encounter an error. */
> + for (i = 0; i < EC_COMMAND_RETRIES; ++i) {
> + usleep_range(10000, 11000);
>
> - /*
> - * Query the EC's status until it's no longer busy or
> - * we encounter an error.
> - */
> - for (i = 0; i < EC_COMMAND_RETRIES; i++) {
> - usleep_range(10000, 11000);
> -
> - trace_cros_ec_request_start(status_msg);
> - ret = (*xfer_fxn)(ec_dev, status_msg);
> - trace_cros_ec_request_done(status_msg, ret);

I'll have to spend more time on this; I don't immediately see (from
the diff) the replacement for the traces, and I don't see what
happened with xfer_fxn.

Guenter

> - if (ret == -EAGAIN)
> - continue;
> - if (ret < 0)
> - break;
> -
> - msg->result = status_msg->result;
> - if (status_msg->result != EC_RES_SUCCESS)
> - break;
> -
> - status = (struct ec_response_get_comms_status *)
> - status_msg->data;
> - if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
> - break;
> - }
> + ret = cros_ec_xfer_command(ec_dev, msg);
> + if (ret == -EAGAIN)
> + continue;
> + if (ret < 0)
> + break;
> +
> + *result = msg->result;
> + if (msg->result != EC_RES_SUCCESS)
> + break;
>
> - kfree(status_msg);
> + if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
> + break;
> }
>
> + kfree(msg);
> + return ret;
> +}
> +
> +static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
> +{
> + int ret = cros_ec_xfer_command(ec_dev, msg);
> +
> + if (msg->result == EC_RES_IN_PROGRESS)
> + ret = cros_ec_wait_until_complete(ec_dev, &msg->result);
> +
> return ret;
> }
>
> --
> 2.36.1.476.g0c4daa206d-goog
>