[src/riastradh-drm2]: src/sys/external/bsd/drm2/include/drm Fix result of DRM...

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

details:   https://anonhg.NetBSD.org/src/rev/224bc8242cae
branches:  riastradh-drm2
changeset: 788542:224bc8242cae
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Sep 08 16:02:50 2013 +0000

description:
Fix result of DRM_TIMED_WAIT_UNTIL.

This has to return a positive number of ticks left if we haven't
timed out in order to match the semantics of Linux waitqueues.

This also fixes the amount of time for timeout if we ever wait for
more than one iteration.

Now we can actually wait for results from the ring buffers!

diffstat:

 sys/external/bsd/drm2/include/drm/drm_wait_netbsd.h |  40 ++++++++++++++++++--
 1 files changed, 35 insertions(+), 5 deletions(-)

diffs (71 lines):

diff -r f1a0bb0ddf93 -r 224bc8242cae sys/external/bsd/drm2/include/drm/drm_wait_netbsd.h
--- a/sys/external/bsd/drm2/include/drm/drm_wait_netbsd.h       Sun Sep 08 16:02:21 2013 +0000
+++ b/sys/external/bsd/drm2/include/drm/drm_wait_netbsd.h       Sun Sep 08 16:02:50 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: drm_wait_netbsd.h,v 1.1.2.6 2013/07/24 03:08:03 riastradh Exp $        */
+/*     $NetBSD: drm_wait_netbsd.h,v 1.1.2.7 2013/09/08 16:02:50 riastradh Exp $        */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -112,13 +112,28 @@
 
 #define        DRM_TIMED_WAIT_UNTIL(RET, Q, INTERLOCK, TICKS, CONDITION) do    \
 {                                                                      \
+       extern int hardclock_ticks;                                     \
+       const int _dtwu_start = hardclock_ticks;                        \
+       int _dtwu_ticks = (TICKS);                                      \
        KASSERT(mutex_is_locked((INTERLOCK)));                          \
-       while (!(CONDITION)) {                                          \
+       for (;;) {                                                      \
+               if (CONDITION) {                                        \
+                       (RET) = _dtwu_ticks;                            \
+                       break;                                          \
+               }                                                       \
                /* XXX errno NetBSD->Linux */                           \
                (RET) = -cv_timedwait_sig((Q), &(INTERLOCK)->mtx_lock,  \
-                   (TICKS));                                           \
+                   _dtwu_ticks);                                       \
                if (RET)                                                \
                        break;                                          \
+               const int _dtwu_now = hardclock_ticks;                  \
+               KASSERT(_dtwu_start <= _dtwu_now);                      \
+               if ((_dtwu_now - _dtwu_start) < _dtwu_ticks) {          \
+                       _dtwu_ticks -= (_dtwu_now - _dtwu_start);       \
+               } else {                                                \
+                       (RET) = 0;                                      \
+                       break;                                          \
+               }                                                       \
        }                                                               \
 } while (0)
 
@@ -136,13 +151,28 @@
 #define        DRM_SPIN_TIMED_WAIT_UNTIL(RET, Q, INTERLOCK, TICKS, CONDITION)  \
        do                                                              \
 {                                                                      \
+       extern int hardclock_ticks;                                     \
+       const int _dstwu_start = hardclock_ticks;                       \
+       int _dstwu_ticks = (TICKS);                                     \
        KASSERT(spin_is_locked((INTERLOCK)));                           \
-       while (!(CONDITION)) {                                          \
+       for (;;) {                                                      \
+               if (CONDITION) {                                        \
+                       (RET) = _dstwu_ticks;                           \
+                       break;                                          \
+               }                                                       \
                /* XXX errno NetBSD->Linux */                           \
                (RET) = -cv_timedwait_sig((Q), &(INTERLOCK)->sl_lock,   \
-                   (TICKS));                                           \
+                   _dstwu_ticks);                                      \
                if (RET)                                                \
                        break;                                          \
+               const int _dstwu_now = hardclock_ticks;                 \
+               KASSERT(_dstwu_start <= _dstwu_now);                    \
+               if ((_dstwu_now - _dstwu_start) < _dstwu_ticks) {       \
+                       _dstwu_ticks -= (_dstwu_now - _dstwu_start);    \
+               } else {                                                \
+                       (RET) = 0;                                      \
+                       break;                                          \
+               }                                                       \
        }                                                               \
 } while (0)