etnaviv: always flush pending queries on get_query_result

This is basically a port from commit 591a3c738d ("freedreno: Be more
strict about QUERY_AVAILABLE to simplify the code.") to etnaviv.

perfmon queries already forced such a flush by setting no_wait_cnt
to a value above the flush threshold, now we unify the behavior between
occlusion and perfmon queries.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30055>

src/gallium/drivers/etnaviv/etnaviv_query_acc.c

@@ -113,31 +113,25 @@ etna_acc_get_query_result(struct etna_context *ctx, struct etna_query *q,
    struct etna_acc_query *aq = etna_acc_query(q);
    struct etna_resource *rsc = etna_resource(aq->prsc);
    const struct etna_acc_sample_provider *p = aq->provider;
+   uint32_t prep_op = DRM_ETNA_PREP_READ;
 
    assert(list_is_empty(&aq->node));
 
-   if (etna_resource_status(ctx, rsc) & ETNA_PENDING_WRITE) {
-      if (!wait) {
-         /* piglit spec@arb_occlusion_query@occlusion_query_conform
-          * test, and silly apps perhaps, get stuck in a loop trying
-          * to get query result forever with wait==false..  we don't
-          * wait to flush unnecessarily but we also don't want to
-          * spin forever.
-          */
-         if (aq->no_wait_cnt++ > 5) {
-            etna_flush(&ctx->base, NULL, 0, true);
-            aq->no_wait_cnt = 0;
-         }
+   /* ARB_occlusion_query says:
+    *     "Querying the state for a given occlusion query forces that
+    *      occlusion query to complete within a finite amount of time."
+    *
+    * So, regardless of whether we are supposed to wait or not, we do need to
+    * flush now.
+    */
+   if (etna_resource_status(ctx, rsc) & ETNA_PENDING_WRITE)
+      etna_flush(&ctx->base, NULL, 0, true);
 
-         return false;
-      } else {
-         /* flush that GPU executes all query related actions */
-         etna_flush(&ctx->base, NULL, 0, true);
-      }
-   }
+   if (!wait)
+      prep_op |= DRM_ETNA_PREP_NOSYNC;
 
    /* get the result */
-   int ret = etna_bo_cpu_prep(rsc->bo, DRM_ETNA_PREP_READ);
+   int ret = etna_bo_cpu_prep(rsc->bo, prep_op);
    if (ret)
       return false;
 

src/gallium/drivers/etnaviv/etnaviv_query_acc.h

@@ -49,7 +49,6 @@ struct etna_acc_query {
 
    struct pipe_resource *prsc;
    unsigned samples;        /* number of samples stored in resource */
-   unsigned no_wait_cnt;    /* see etna_hw_get_query_result() */
    struct list_head node;   /* list-node in ctx->active_hw_queries */
 
    const struct etna_acc_sample_provider *provider;

src/gallium/drivers/etnaviv/etnaviv_query_acc_perfmon.c

@@ -90,9 +90,6 @@ pm_query(struct etna_context *ctx, struct etna_acc_query *aq, unsigned flags)
 
    etna_cmd_stream_perf(stream, &p);
    resource_written(ctx, aq->prsc);
-
-   /* force a flush in !wait case in etna_acc_get_query_result(..) */
-   aq->no_wait_cnt = 10;
 }
 
 static bool