Module Name: src
Committed By: sekiya
Date: Fri Aug 5 21:03:43 UTC 2022
Modified Files:
src/sys/dev/ic: dwc_gmac.c
Log Message:
Do not unilaterally set M_HASFCS; this breaks protocols that lack CRC bytes
(such as AppleTalk).
Instead, remove/preserve the final four bytes in the packet ourselves on a per-
protocol basis, as we do in arch/arm/xscale/ixp425_if_npe.c (and dev/ic/gem.c,
and so forth).
To generate a diff of this commit:
cvs rdiff -u -r1.75 -r1.76 src/sys/dev/ic/dwc_gmac.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/ic/dwc_gmac.c
diff -u src/sys/dev/ic/dwc_gmac.c:1.75 src/sys/dev/ic/dwc_gmac.c:1.76
--- src/sys/dev/ic/dwc_gmac.c:1.75 Sat Sep 11 20:28:06 2021
+++ src/sys/dev/ic/dwc_gmac.c Fri Aug 5 21:03:43 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: dwc_gmac.c,v 1.75 2021/09/11 20:28:06 andvar Exp $ */
+/* $NetBSD: dwc_gmac.c,v 1.76 2022/08/05 21:03:43 sekiya Exp $ */
/*-
* Copyright (c) 2013, 2014 The NetBSD Foundation, Inc.
@@ -41,7 +41,7 @@
#include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: dwc_gmac.c,v 1.75 2021/09/11 20:28:06 andvar Exp $");
+__KERNEL_RCSID(1, "$NetBSD: dwc_gmac.c,v 1.76 2022/08/05 21:03:43 sekiya Exp $");
/* #define DWC_GMAC_DEBUG 1 */
@@ -1229,6 +1229,8 @@ dwc_gmac_rx_intr(struct dwc_gmac_softc *
struct mbuf *m, *mnew;
int i, len, error;
+ uint16_t etype;
+
mutex_enter(&sc->sc_rxq.r_mtx);
for (i = sc->sc_rxq.r_cur; ; i = RX_NEXT(i)) {
bus_dmamap_sync(sc->sc_dmat, sc->sc_dma_ring_map,
@@ -1311,8 +1313,29 @@ dwc_gmac_rx_intr(struct dwc_gmac_softc *
/* finalize mbuf */
m->m_pkthdr.len = m->m_len = len;
m_set_rcvif(m, ifp);
- m->m_flags |= M_HASFCS;
+#define ETYPE_OFFSET 20
+ etype = (m->m_data[ETYPE_OFFSET] << 8) + m->m_data[ETYPE_OFFSET+1];
+
+ /*
+ * The hardware doesn't trim the four FCS bytes for us, so
+ * we need to trim it ourselves.
+ * Having the upper layer remove it by passing M_HASFCS breaks
+ * protocols that don't have FCS bytes at the end of the packet
+ * (AppleTalk, for example), so we do it here instead.
+ */
+
+ switch (etype) {
+ case ETHERTYPE_ATALK:
+ case ETHERTYPE_AARP:
+ /* No FCS removal needed */
+ break;
+ default:
+ /* remove FCS */
+ m_adj(m, -ETHER_CRC_LEN);
+ break;
+ }
+
if_percpuq_enqueue(sc->sc_ipq, m);
skip:
