Patch "platform/chrome: cros_ec_lightbar: Reduce ligthbar get version command" has been added to the 5.9-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    platform/chrome: cros_ec_lightbar: Reduce ligthbar get version command

to the 5.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     platform-chrome-cros_ec_lightbar-reduce-ligthbar-get.patch
and it can be found in the queue-5.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c487be006a458fcdeebcfdb6f548579bc31f1ad6
Author: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Date:   Sat Aug 29 23:59:37 2020 -0700

    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@xxxxxxxxxxxx>
    Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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;