#12855: Fix unpacker race condition by putting stall after MMIO

tenstorrent · Nov 5, 2024 · 5375c5e · 5375c5e
1 parent 45dc5cc
commit 5375c5e
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/llk_lib/llk_unpack_AB_matmul.h b/llk_lib/llk_unpack_AB_matmul.h
@@ -236,8 +236,6 @@ inline void _llk_unpack_AB_matmul_(
         // Wait for free context
         wait_for_next_context(2);
 
-        semaphore_post(semaphore::UNPACK_SYNC);  // Trisc::SEMPOST for context acquire
-
         // Program unpacker 1 base address
         if (0 == unp_cfg_context) {
             cfg[THCON_SEC0_REG3_Base_address_ADDR32] = address_b;
@@ -247,6 +245,11 @@ inline void _llk_unpack_AB_matmul_(
             cfg[THCON_SEC1_REG3_Base_cntx1_address_ADDR32] = address_a;
         }
 
+        semaphore_post(semaphore::UNPACK_SYNC);  // Trisc::SEMPOST for context acquire
+
+        // Stall unpacker until pending CFG writes from Trisc have completed
+        TTI_STALLWAIT(p_stall::STALL_UNPACK, p_stall::TRISC_CFG);
+
         if (reuse_a) {
             #if SKIP_UNP == 1
                 TTI_NOP;