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@xxxxxxxxxxxx> --- 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; -- 2.28.0.297.g1956fa8f8d-goog