svn commit: r304603 - head/sys/dev/ioat

[Conrad E. Meyer]

Author: cem
Date: Mon Aug 22 14:51:09 2016
New Revision: 304603
URL: https://svnweb.freebsd.org/changeset/base/304603

Log:
  ioat(4): Allow callouts to be scheduled after hw reset
  
  is_completion_pending governs whether or not a callout will be scheduled
  when new work is queued on the IOAT device.  If true, a callout is
  already scheduled, so we do not need a new one.  If false, we schedule
  one and set it true.  Because resetting the hardware completed all
  outstanding work but failed to clear is_completion_pending, no new
  callout could be scheduled after a reset with pending work.
  
  This resulted in a driver hang for polled-only work.

Modified:
  head/sys/dev/ioat/ioat.c

Modified: head/sys/dev/ioat/ioat.c
==============================================================================
--- head/sys/dev/ioat/ioat.c	Mon Aug 22 14:51:07 2016	(r304602)
+++ head/sys/dev/ioat/ioat.c	Mon Aug 22 14:51:09 2016	(r304603)
@@ -768,6 +768,13 @@ ioat_process_events(struct ioat_softc *i
 		ioat->stats.descriptors_error++;
 	}
 
+	if (ioat->is_completion_pending) {
+		ioat->is_completion_pending = FALSE;
+		callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
+		    ioat_shrink_timer_callback, ioat);
+		callout_stop(&ioat->poll_timer);
+	}
+
 	/* Clear error status */
 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
 
@@ -1898,6 +1905,7 @@ ioat_reset_hw(struct ioat_softc *ioat)
 	ioat->tail = ioat->head = ioat->hw_head = 0;
 	ioat->last_seen = 0;
 	*ioat->comp_update = 0;
+	KASSERT(!ioat->is_completion_pending, ("bogus completion_pending"));
 
 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);