[bug report] platform/surface: Add Surface Aggregator subsystem

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Maximilian Luz,

The patch c167b9c7e3d6: "platform/surface: Add Surface Aggregator
subsystem" from Dec 21, 2020, leads to the following static checker
warning:

	drivers/platform/surface/aggregator/ssh_packet_layer.c:1697 ssh_ptl_rx_eval()
	warn: check likely/unlikely parens

drivers/platform/surface/aggregator/ssh_packet_layer.c
  1683  static size_t ssh_ptl_rx_eval(struct ssh_ptl *ptl, struct ssam_span *source)
  1684  {
  1685          struct ssh_frame *frame;
  1686          struct ssam_span payload;
  1687          struct ssam_span aligned;
  1688          bool syn_found;
  1689          int status;
  1690  
  1691          /* Error injection: Modify data to simulate corrupt SYN bytes. */
  1692          ssh_ptl_rx_inject_invalid_syn(ptl, source);
  1693  
  1694          /* Find SYN. */
  1695          syn_found = sshp_find_syn(source, &aligned);
  1696  
  1697          if (unlikely(aligned.ptr - source->ptr) > 0) {

The unlikely() macro returns 0/1.  Smatch is suggesting that this should
just be "if (unlikely((aligned.ptr - source->ptr) > 0)) {" but I'm not
at all sure that that's correct.  Isn't aligned being higher than source
the normal case?

  1698                  ptl_warn(ptl, "rx: parser: invalid start of frame, skipping\n");
  1699  
  1700                  /*
  1701                   * Notes:
  1702                   * - This might send multiple NAKs in case the communication

regards,
dan carpenter