[src/riastradh-drm2]: src/sys/external/bsd/drm2/linux Fix queue_delayed_work ...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a165bd6c9db6
branches:  riastradh-drm2
changeset: 788621:a165bd6c9db6
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Jan 22 14:58:20 2014 +0000

description:
Fix queue_delayed_work edge cases.

- Copy the relevant part of queue_work in-line for ticks == 0, since
  queue_work itself will choke on a delayed work.

- Don't reschedule the callout if it is already scheduled -- let it
  fire when it was already scheduled to fire.

diffstat:

 sys/external/bsd/drm2/linux/linux_work.c |  35 +++++++++++++++++++------------
 1 files changed, 21 insertions(+), 14 deletions(-)

diffs (63 lines):

diff -r e654a6ca8280 -r a165bd6c9db6 sys/external/bsd/drm2/linux/linux_work.c
--- a/sys/external/bsd/drm2/linux/linux_work.c  Wed Jan 22 14:58:12 2014 +0000
+++ b/sys/external/bsd/drm2/linux/linux_work.c  Wed Jan 22 14:58:20 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux_work.c,v 1.1.2.8 2013/12/30 04:52:21 riastradh Exp $     */
+/*     $NetBSD: linux_work.c,v 1.1.2.9 2014/01/22 14:58:20 riastradh Exp $     */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_work.c,v 1.1.2.8 2013/12/30 04:52:21 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_work.c,v 1.1.2.9 2014/01/22 14:58:20 riastradh Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -512,25 +512,32 @@
 
        KASSERT(wq != NULL);
 
-       /* If we're not actually delaying, queue the work now.  */
-       if (ticks == 0) {
-               queue_work(wq, &dw->work);
-               return;
-       }
-
        linux_work_lock(&dw->work);
        switch (dw->work.w_state) {
        case WORK_IDLE:
        case WORK_INVOKED:
-               callout_init(&dw->dw_callout, CALLOUT_MPSAFE);
-               callout_reset(&dw->dw_callout, ticks, &linux_worker_intr, dw);
-               dw->work.w_state = WORK_DELAYED;
-               dw->work.w_wq = wq;
-               TAILQ_INSERT_HEAD(&wq->wq_delayed, dw, dw_entry);
+               if (ticks == 0) {
+                       /* Skip the delay and queue it now.  */
+                       dw->work.w_state = WORK_PENDING;
+                       dw->work.w_wq = wq;
+                       workqueue_enqueue(wq->wq_workqueue, &dw->work.w_wk,
+                           NULL);
+               } else {
+                       callout_init(&dw->dw_callout, CALLOUT_MPSAFE);
+                       callout_reset(&dw->dw_callout, ticks,
+                           &linux_worker_intr, dw);
+                       dw->work.w_state = WORK_DELAYED;
+                       dw->work.w_wq = wq;
+                       TAILQ_INSERT_HEAD(&wq->wq_delayed, dw, dw_entry);
+               }
                break;
 
        case WORK_DELAYED:
-               callout_schedule(&dw->dw_callout, ticks);
+               /*
+                * Timer is already ticking.  Leave it to time out
+                * whenever it was going to time out, as Linux does --
+                * neither speed it up nor postpone it.
+                */
                break;
 
        case WORK_PENDING: