+ /* From the SKL PRM, Workarounds section (#878):
+ *
+ * Push constant buffer corruption possible. WA: Insert 2 zero-length
+ * PushConst_PS before every intended PushConst_PS update, issue a
+ * NULLPRIM after each of the zero len PC update to make sure CS commits
+ * them.
+ *
+ * This workaround is attempting to solve a pixel shader push constant
+ * synchronization issue.
+ *
+ * There's an unpublished WA that involves re-emitting
+ * 3DSTATE_PUSH_CONSTANT_ALLOC_PS for every 500-ish 3DSTATE_CONSTANT_PS
+ * packets. Since our counting methods may not be reliable due to
+ * context-switching and pre-emption, we instead choose to approximate this
+ * behavior by re-emitting the packet at the top of the batch.
+ */
+ if (brw->ctx.NewDriverState == BRW_NEW_BATCH) {
+ /* SKL GT2 and GLK 2x6 have reliably demonstrated this issue thus far.
+ * We've also seen some intermittent failures from SKL GT4 and BXT in
+ * the past.
+ */
+ if (!devinfo->is_skylake &&
+ !devinfo->is_broxton &&
+ !devinfo->is_geminilake)
+ return;
+ }
+