Module Name: src
Committed By: riastradh
Date: Tue Jul 19 08:22:34 UTC 2022
Modified Files:
src/sys/dev/pci: if_wm.c
Log Message:
wm(4): Use CSR_WRITE_FLUSH, not bus_space_barrier.
The bus space is mapped non-prefetchable and non-cacheable, so there
is no need for bus_space_barrier and it might not even have any
effect -- bus_space_read/write are totally ordered for non-
prefetchable, non-cacheable mappings anyway. Presumably the intent
here was to wait for acknowledgment of the write from the device --
which bus_space_barrier does not guarantee, and which I expect
requires a read transaction as CSR_WRITE_FLUSH performs.
ok msaitoh@, knakahara@
To generate a diff of this commit:
cvs rdiff -u -r1.744 -r1.745 src/sys/dev/pci/if_wm.c
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/pci/if_wm.c
diff -u src/sys/dev/pci/if_wm.c:1.744 src/sys/dev/pci/if_wm.c:1.745
--- src/sys/dev/pci/if_wm.c:1.744 Tue Jul 19 08:21:02 2022
+++ src/sys/dev/pci/if_wm.c Tue Jul 19 08:22:34 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: if_wm.c,v 1.744 2022/07/19 08:21:02 riastradh Exp $ */
+/* $NetBSD: if_wm.c,v 1.745 2022/07/19 08:22:34 riastradh Exp $ */
/*
* Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -82,7 +82,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.744 2022/07/19 08:21:02 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.745 2022/07/19 08:22:34 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_net_mpsafe.h"
@@ -4923,8 +4923,7 @@ wm_flush_desc_rings(struct wm_softc *sc)
txq->txq_next = WM_NEXTTX(txq, txq->txq_next);
CSR_WRITE(sc, WMREG_TDT(0), txq->txq_next);
- bus_space_barrier(sc->sc_st, sc->sc_sh, 0, 0,
- BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
+ CSR_WRITE_FLUSH(sc);
delay(250);
preg = pci_conf_read(sc->sc_pc, sc->sc_pcitag, WM_PCI_DESCRING_STATUS);
