From 1e7913ff5f9f1b73146ad8522958bd266f22a510 Mon Sep 17 00:00:00 2001
From: Gwendal Grignou <gwendal@chromium.org>
Date: Sat, 29 Aug 2020 23:59:37 -0700
Subject: [PATCH] platform/chrome: cros_ec_lightbar: Reduce ligthbar get
 version command
Git-commit: 1e7913ff5f9f1b73146ad8522958bd266f22a510
References: git-fixes
Patch-mainline: v5.10-rc1

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: Oliver Neukum <oneukum@suse.com>
---
 drivers/platform/chrome/cros_ec_lightbar.c |    2 ++
 1 file changed, 2 insertions(+)

--- 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 c
 
 	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(ec->ec_dev, msg);
 	if (ret < 0) {
 		ret = 0;