Mesa (master): gallium: fix PIPE_QUERY_TIMESTAMP_DISJOINT

[Roland Scheidegger]

Module: Mesa
Branch: master
Commit: cdf89d0b5c3fccefe573d5adf731dd8fb900b74e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=cdf89d0b5c3fccefe573d5adf731dd8fb900b74e

Author: Roland Scheidegger <sroland at vmware.com>
Date:   Wed Jun 19 23:25:39 2013 +0200

gallium: fix PIPE_QUERY_TIMESTAMP_DISJOINT

The semantics didn't really make sense, not really matching neither d3d9
(though the docs are all broken there) nor d3d10. So make it match d3d10
semantics, which actually gives meaning to the "disjoint" part.
Drivers are fixed up in a very primitive way, I have no idea what could
actually cause the counter to become unreliable so just always return
FALSE for the disjoint part.

Reviewed-by: Jose Fonseca <jfonseca at vmware.com>

---

 src/gallium/docs/source/context.rst   |   10 ++++++----
 src/gallium/drivers/nv50/nv50_query.c |    8 ++++----
 src/gallium/drivers/nvc0/nvc0_query.c |    6 ++----
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/gallium/docs/source/context.rst b/src/gallium/docs/source/context.rst
index ede89be..bfd58a4 100644
--- a/src/gallium/docs/source/context.rst
+++ b/src/gallium/docs/source/context.rst
@@ -330,11 +330,13 @@ scaled to nanoseconds, recorded after all commands issued prior to
 This query does not require a call to ``begin_query``.
 The result is an unsigned 64-bit integer.
 
-``PIPE_QUERY_TIMESTAMP_DISJOINT`` can be used to check whether the
-internal timer resolution is good enough to distinguish between the
-events at ``begin_query`` and ``end_query``.
+``PIPE_QUERY_TIMESTAMP_DISJOINT`` can be used to check the
+internal timer resolution and whether the timestamp counter has become
+unreliable due to things like throttling etc. - only if this is FALSE
+a timestamp query (within the timestamp_disjoint query) should be trusted.
 The result is a 64-bit integer specifying the timer resolution in Hz,
-followed by a boolean value indicating whether the timer has incremented.
+followed by a boolean value indicating whether the timestamp counter
+is discontinuous or disjoint.
 
 ``PIPE_QUERY_PRIMITIVES_GENERATED`` returns a 64-bit integer indicating
 the number of primitives processed by the pipeline (regardless of whether
diff --git a/src/gallium/drivers/nv50/nv50_query.c b/src/gallium/drivers/nv50/nv50_query.c
index 656ff9d..34456a9 100644
--- a/src/gallium/drivers/nv50/nv50_query.c
+++ b/src/gallium/drivers/nv50/nv50_query.c
@@ -181,7 +181,6 @@ nv50_query_begin(struct pipe_context *pipe, struct pipe_query *pq)
       nv50_query_get(push, q, 0x20, 0x05805002);
       nv50_query_get(push, q, 0x30, 0x06805002);
       break;
-   case PIPE_QUERY_TIMESTAMP_DISJOINT:
    case PIPE_QUERY_TIME_ELAPSED:
       nv50_query_get(push, q, 0x10, 0x00005002);
       break;
@@ -218,7 +217,6 @@ nv50_query_end(struct pipe_context *pipe, struct pipe_query *pq)
    case PIPE_QUERY_TIMESTAMP:
       q->sequence++;
       /* fall through */
-   case PIPE_QUERY_TIMESTAMP_DISJOINT:
    case PIPE_QUERY_TIME_ELAPSED:
       nv50_query_get(push, q, 0, 0x00005002);
       break;
@@ -229,6 +227,8 @@ nv50_query_end(struct pipe_context *pipe, struct pipe_query *pq)
    case NVA0_QUERY_STREAM_OUTPUT_BUFFER_OFFSET:
       nv50_query_get(push, q, 0, 0x0d005002 | (q->index << 5));
       break;
+   case PIPE_QUERY_TIMESTAMP_DISJOINT:
+      break;
    default:
       assert(0);
       break;
@@ -287,9 +287,9 @@ nv50_query_result(struct pipe_context *pipe, struct pipe_query *pq,
    case PIPE_QUERY_TIMESTAMP:
       res64[0] = data64[1];
       break;
-   case PIPE_QUERY_TIMESTAMP_DISJOINT: /* u32 sequence, u32 0, u64 time */
+   case PIPE_QUERY_TIMESTAMP_DISJOINT:
       res64[0] = 1000000000;
-      res8[8] = (data64[1] == data64[3]) ? FALSE : TRUE;
+      res8[8] = FALSE;
       break;
    case PIPE_QUERY_TIME_ELAPSED:
       res64[0] = data64[1] - data64[3];
diff --git a/src/gallium/drivers/nvc0/nvc0_query.c b/src/gallium/drivers/nvc0/nvc0_query.c
index 8e584c9..75c515a 100644
--- a/src/gallium/drivers/nvc0/nvc0_query.c
+++ b/src/gallium/drivers/nvc0/nvc0_query.c
@@ -285,7 +285,6 @@ nvc0_query_begin(struct pipe_context *pipe, struct pipe_query *pq)
    case PIPE_QUERY_SO_OVERFLOW_PREDICATE:
       nvc0_query_get(push, q, 0x10, 0x03005002 | (q->index << 5));
       break;
-   case PIPE_QUERY_TIMESTAMP_DISJOINT:
    case PIPE_QUERY_TIME_ELAPSED:
       nvc0_query_get(push, q, 0x10, 0x00005002);
       break;
@@ -360,7 +359,6 @@ nvc0_query_end(struct pipe_context *pipe, struct pipe_query *pq)
       nvc0_query_get(push, q, 0x20, 0x00005002);
       break;
    case PIPE_QUERY_TIMESTAMP:
-   case PIPE_QUERY_TIMESTAMP_DISJOINT:
    case PIPE_QUERY_TIME_ELAPSED:
       nvc0_query_get(push, q, 0, 0x00005002);
       break;
@@ -476,9 +474,9 @@ nvc0_query_result(struct pipe_context *pipe, struct pipe_query *pq,
    case PIPE_QUERY_TIMESTAMP:
       res64[0] = data64[1];
       break;
-   case PIPE_QUERY_TIMESTAMP_DISJOINT: /* u32 sequence, u32 0, u64 time */
+   case PIPE_QUERY_TIMESTAMP_DISJOINT:
       res64[0] = 1000000000;
-      res8[8] = (data64[1] == data64[3]) ? FALSE : TRUE;
+      res8[8] = FALSE;
       break;
    case PIPE_QUERY_TIME_ELAPSED:
       res64[0] = data64[1] - data64[3];