platform/chrome: cros_ec_lightbar: Reduce ligthbar get version command

[ Upstream commit 1e7913ff5f9f1b73146ad8522958bd266f22a510 ]

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

Fixes: a841178445bb7 ("mfd: cros_ec: Use a zero-length array for command data")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
index b59180bff5a3e067cbfc5ac3d37d40204f9d4a18..ef61298c30bdde60bea4336782112897bfe2cb25 100644 (file)
--- 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;