Module Name: src
Committed By: rin
Date: Thu Mar 25 05:34:49 UTC 2021
Modified Files:
src/sys/dev/ic: com.c comvar.h
Log Message:
Introduce COM_HW_BROKEN_ETXRDY bit in sc_hwflags; push TX queue if
possible in comintr() even if IIR_NOPEND is asserted.
Combined with sc_poll_ticks, this flag works around HW bug, by which
ETXRDY interrupts are (sometimes) lost.
To generate a diff of this commit:
cvs rdiff -u -r1.362 -r1.363 src/sys/dev/ic/com.c
cvs rdiff -u -r1.93 -r1.94 src/sys/dev/ic/comvar.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/ic/com.c
diff -u src/sys/dev/ic/com.c:1.362 src/sys/dev/ic/com.c:1.363
--- src/sys/dev/ic/com.c:1.362 Thu Mar 25 05:33:59 2021
+++ src/sys/dev/ic/com.c Thu Mar 25 05:34:49 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: com.c,v 1.362 2021/03/25 05:33:59 rin Exp $ */
+/* $NetBSD: com.c,v 1.363 2021/03/25 05:34:49 rin 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 1.362 2021/03/25 05:33:59 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: com.c,v 1.363 2021/03/25 05:34:49 rin Exp $");
#include "opt_com.h"
#include "opt_ddb.h"
@@ -2162,15 +2162,17 @@ comintr(void *arg)
}
}
+ end = sc->sc_ebuf;
+ put = sc->sc_rbput;
+ cc = sc->sc_rbavail;
+
if (ISSET(iir, IIR_NOPEND)) {
+ if (ISSET(sc->sc_hwflags, COM_HW_BROKEN_ETXRDY))
+ goto do_tx;
mutex_spin_exit(&sc->sc_lock);
return (0);
}
- end = sc->sc_ebuf;
- put = sc->sc_rbput;
- cc = sc->sc_rbavail;
-
again: do {
u_char msr, delta;
@@ -2306,6 +2308,7 @@ again: do {
*/
(iir & IIR_IMASK) != IIR_TXRDY);
+do_tx:
/*
* Read LSR again, since there may be an interrupt between
* the last LSR read and IIR read above.
@@ -2358,7 +2361,8 @@ again: do {
mutex_spin_exit(&sc->sc_lock);
/* Wake up the poller. */
- softint_schedule(sc->sc_si);
+ if ((sc->sc_rx_ready | sc->sc_st_check | sc->sc_tx_done) != 0)
+ softint_schedule(sc->sc_si);
#ifdef RND_COM
rnd_add_uint32(&sc->rnd_source, iir | lsr);
Index: src/sys/dev/ic/comvar.h
diff -u src/sys/dev/ic/comvar.h:1.93 src/sys/dev/ic/comvar.h:1.94
--- src/sys/dev/ic/comvar.h:1.93 Thu Mar 25 05:33:59 2021
+++ src/sys/dev/ic/comvar.h Thu Mar 25 05:34:49 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: comvar.h,v 1.93 2021/03/25 05:33:59 rin Exp $ */
+/* $NetBSD: comvar.h,v 1.94 2021/03/25 05:34:49 rin Exp $ */
/*
* Copyright (c) 1996 Christopher G. Demetriou. All rights reserved.
@@ -61,7 +61,7 @@ int com_is_console(bus_space_tag_t, bus_
/* Hardware flag masks */
#define COM_HW_NOIEN 0x01
#define COM_HW_FIFO 0x02
- /* 0x04 free for use */
+#define COM_HW_BROKEN_ETXRDY 0x04
#define COM_HW_FLOW 0x08
#define COM_HW_DEV_OK 0x20
#define COM_HW_CONSOLE 0x40
