From 41f3aaf426830630eac9e77d8f4f8d023bf78b40 Mon Sep 17 00:00:00 2001
From: jmcneill <jmcneill@NetBSD.org>
Date: Mon, 28 Dec 2020 16:49:58 +0000
Subject: [PATCH] Initialize DMA memory when allocating it. Should fix PR#
 51734 (hdaudio "RIRB timeout" on boot).

---
 sys/dev/hdaudio/hdaudio.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sys/dev/hdaudio/hdaudio.c b/sys/dev/hdaudio/hdaudio.c
index 3533c800aa83..c1e6b716aa93 100644
--- a/sys/dev/hdaudio/hdaudio.c
+++ b/sys/dev/hdaudio/hdaudio.c
@@ -1,4 +1,4 @@
-/* $NetBSD: hdaudio.c,v 1.11 2020/06/11 02:39:30 thorpej Exp $ */
+/* $NetBSD: hdaudio.c,v 1.12 2020/12/28 16:49:58 jmcneill Exp $ */
 
 /*
  * Copyright (c) 2009 Precedence Technologies Ltd <support@precedence.co.uk>
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: hdaudio.c,v 1.11 2020/06/11 02:39:30 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: hdaudio.c,v 1.12 2020/12/28 16:49:58 jmcneill Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -179,6 +179,10 @@ hdaudio_dma_alloc(struct hdaudio_softc *sc, struct hdaudio_dma *dma,
 	if (err)
 		goto destroy;
 
+	memset(dma->dma_addr, 0, dma->dma_size);
+	bus_dmamap_sync(sc->sc_dmat, dma->dma_map, 0, dma->dma_size,
+	    BUS_DMASYNC_PREWRITE);
+
 	dma->dma_valid = true;
 	return 0;