drm/etnaviv: restore ETNA_PREP_NOSYNC behaviour

This reverts commit cd34db4a526c (drm/etnaviv: Remove manual call to
reservation_object_test_signaled_rcu before wait), as the patch to turn
reservation_object_wait_timeout_rcu() into
reservation_object_test_signaled_rcu() with a 0 timeout has been reverted.
This causes the driver to call into the fence wait, even with a timeout of 0

The etnaviv BO cache depends on ETNA_PREP_NOSYNC to be wait-free, even if
the BO has attached fences, so restore the behaviour for this flag.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index fd56f92..f0efc5d 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -411,16 +411,20 @@ int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op,
        struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
        struct drm_device *dev = obj->dev;
        bool write = !!(op & ETNA_PREP_WRITE);
-       unsigned long remain =
-               op & ETNA_PREP_NOSYNC ? 0 : etnaviv_timeout_to_jiffies(timeout);
-       long lret;
-
-       lret = reservation_object_wait_timeout_rcu(etnaviv_obj->resv,
-                                                  write, true, remain);
-       if (lret < 0)
-               return lret;
-       else if (lret == 0)
-               return remain == 0 ? -EBUSY : -ETIMEDOUT;
+       int ret;
+
+       if (op & ETNA_PREP_NOSYNC) {
+               if (!reservation_object_test_signaled_rcu(etnaviv_obj->resv,
+                                                         write))
+                       return -EBUSY;
+       } else {
+               unsigned long remain = etnaviv_timeout_to_jiffies(timeout);
+
+               ret = reservation_object_wait_timeout_rcu(etnaviv_obj->resv,
+                                                         write, true, remain);
+               if (ret <= 0)
+                       return ret == 0 ? -ETIMEDOUT : ret;
+       }
 
        if (etnaviv_obj->flags & ETNA_BO_CACHED) {
                if (!etnaviv_obj->sgt) {