8634 epoll fails to wake on certain edge-triggered conditions
8635 epoll should not emit POLLNVAL
8636 recursive epoll should emit EPOLLRDNORM
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>

*** 18,28 ****
   *
   * CDDL HEADER END
   */
  
  /*
!  * Copyright (c) 2013, Joyent, Inc.  All rights reserved.
   * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
   */
  
  /*
   * The ipmi driver is an openipmi compatible IPMI driver based on the FreeBSD
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  
  /*
!  * Copyright 2017 Joyent, Inc.
   * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
   */
  
  /*
   * The ipmi driver is an openipmi compatible IPMI driver based on the FreeBSD
*** 458,470 ****
                          revent |= events & (POLLIN | POLLRDNORM);
                  if (dev->ipmi_requests == 0)
                          revent |= POLLERR;
          }
  
!         if (revent == 0) {
!                 /* nothing has occurred */
!                 if (!anyyet)
                          *phpp = dev->ipmi_pollhead;
          }
  
          *reventsp = revent;
          return (0);
--- 458,468 ----
                          revent |= events & (POLLIN | POLLRDNORM);
                  if (dev->ipmi_requests == 0)
                          revent |= POLLERR;
          }
  
!         if ((revent == 0 && !anyyet) || (events & POLLET)) {
                  *phpp = dev->ipmi_pollhead;
          }
  
          *reventsp = revent;
          return (0);