platform/chrome: cros_ec_proto: return 0 on getting cmd mask success

cros_ec_get_host_command_version_mask() used to return value from
send_command() which is number of available bytes for input payload on
success (i.e. sizeof(struct ec_response_get_cmd_versions)).

However, the callers don't need to know how many bytes are available.

Don't return number of available bytes.  Instead, return 0 on success;
otherwise, negative integers on error.

Also remove the unneeded `ver_mask` initialization as the callers should
take it only if cros_ec_get_host_command_version_mask() returns 0.

Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220609084957.3684698-15-tzungbi@kernel.org

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 630d7ee5392a423d4dd67803b24c356f4691b750..1df22eb29e95c153c0c182c37f708f932f1dfb60 100644 (file)
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -453,6 +453,7 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
        if (ret > 0) {
                rver = (struct ec_response_get_cmd_versions *)msg->data;
                *mask = rver->version_mask;
+               ret = 0;
        }
 
        kfree(msg);
@@ -470,7 +471,7 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
 int cros_ec_query_all(struct cros_ec_device *ec_dev)
 {
        struct device *dev = ec_dev->dev;
-       u32 ver_mask = 0;
+       u32 ver_mask;
        int ret;
 
        /* First try sending with proto v3. */
@@ -509,9 +510,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
        }
 
        /* Probe if MKBP event is supported */
-       ret = cros_ec_get_host_command_version_mask(ec_dev,
-                                                   EC_CMD_GET_NEXT_EVENT,
-                                                   &ver_mask);
+       ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
        if (ret < 0 || ver_mask == 0) {
                ec_dev->mkbp_event_supported = 0;
        } else {
@@ -521,10 +520,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
        }
 
        /* Probe if host sleep v1 is supported for S0ix failure detection. */
-       ret = cros_ec_get_host_command_version_mask(ec_dev,
-                                                   EC_CMD_HOST_SLEEP_EVENT,
-                                                   &ver_mask);
-       ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
+       ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
+       ec_dev->host_sleep_v1 = (ret == 0 && (ver_mask & EC_VER_MASK(1)));
 
        /* Get host event wake mask. */
        ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);