iio: cros_ec: Avoid -Wflex-array-member-not-at-end warning

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with these changes, fix the following warning:

drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c:39:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/Z9lE6IVDeC5lnChN@kspp
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 7751d6f69b124145f56f4bb892fa9ab514a52909..40d5b10c74e082888cc5c1dd909eadff76162cbf 100644 (file)
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -34,25 +34,19 @@
 static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
                                             u16 cmd_offset, u16 cmd, u32 *mask)
 {
+       DEFINE_RAW_FLEX(struct cros_ec_command, buf, data,
+                       MAX(sizeof(struct ec_response_get_cmd_versions),
+                           sizeof(struct ec_params_get_cmd_versions)));
        int ret;
-       struct {
-               struct cros_ec_command msg;
-               union {
-                       struct ec_params_get_cmd_versions params;
-                       struct ec_response_get_cmd_versions resp;
-               };
-       } __packed buf = {
-               .msg = {
-                       .command = EC_CMD_GET_CMD_VERSIONS + cmd_offset,
-                       .insize = sizeof(struct ec_response_get_cmd_versions),
-                       .outsize = sizeof(struct ec_params_get_cmd_versions)
-                       },
-               .params = {.cmd = cmd}
-       };
-
-       ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
+
+       buf->command = EC_CMD_GET_CMD_VERSIONS + cmd_offset;
+       buf->insize = sizeof(struct ec_response_get_cmd_versions);
+       buf->outsize = sizeof(struct ec_params_get_cmd_versions);
+       ((struct ec_params_get_cmd_versions *)buf->data)->cmd = cmd;
+
+       ret = cros_ec_cmd_xfer_status(ec_dev, buf);
        if (ret >= 0)
-               *mask = buf.resp.version_mask;
+               *mask = ((struct ec_response_get_cmd_versions *)buf->data)->version_mask;
        return ret;
 }