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authorjmcneill <jmcneill@NetBSD.org>2021-10-30 11:43:17 +0000
committerjmcneill <jmcneill@NetBSD.org>2021-10-30 11:43:17 +0000
commit50af335bc66bd7eabbbbd298ac039e48cbfab3a3 (patch)
treec2994bd0f0c0f802f04bfdff806a698f2ef38b32 /sys/dev/ic
parentf000cb62aa1b2a6e740deb588405481ce7dfecc9 (diff)
For the DW APB busy bit workaround, only attempt to re-apply LCR and DLB
settings for non-console devices. In the console case, simply clear the busy bit and continue. Fixes an interrupt storm observed on Macchiatobin.
Diffstat (limited to 'sys/dev/ic')
-rw-r--r--sys/dev/ic/com.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/sys/dev/ic/com.c b/sys/dev/ic/com.c
index b1603e3d2fa..83213fc24f6 100644
--- a/sys/dev/ic/com.c
+++ b/sys/dev/ic/com.c
@@ -1,4 +1,4 @@
-/* $NetBSD: com.c,v 1.371 2021/10/21 10:22:54 jmcneill Exp $ */
+/* $NetBSD: com.c,v 1.372 2021/10/30 11:43:17 jmcneill Exp $ */
/*-
* Copyright (c) 1998, 1999, 2004, 2008 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: com.c,v 1.371 2021/10/21 10:22:54 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: com.c,v 1.372 2021/10/30 11:43:17 jmcneill Exp $");
#include "opt_com.h"
#include "opt_ddb.h"
@@ -2147,7 +2147,9 @@ comintr(void *arg)
/* DesignWare APB UART BUSY interrupt */
if (sc->sc_type == COM_TYPE_DW_APB &&
(iir & IIR_BUSY) == IIR_BUSY) {
- if ((CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0) {
+ if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
+ (void)CSR_READ_1(regsp, COM_REG_USR);
+ } else if ((CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0) {
CSR_WRITE_1(regsp, COM_REG_HALT, HALT_CHCFG_EN);
CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);