gianfar: Fall back to software tcp/udp checksum on older controllers
As specified by errata eTSEC49 of MPC8548 and errata eTSEC12 of MPC83xx,
older revisions of gianfar controllers will be unable to calculate a TCP/UDP
packet checksum for some alignments of the appropriate FCB. This patch checks
for FCB alignment on such controllers and falls back to software checksumming
if the alignment is known to be bad.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index ccb231c..2a0ad9a 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -949,6 +949,11 @@
(pvr == 0x80861010 && (mod & 0xfff9) == 0x80c0))
priv->errata |= GFAR_ERRATA_A002;
+ /* MPC8313 Rev < 2.0, MPC8548 rev 2.0 */
+ if ((pvr == 0x80850010 && mod == 0x80b0 && rev < 0x0020) ||
+ (pvr == 0x80210020 && mod == 0x8030 && rev == 0x0020))
+ priv->errata |= GFAR_ERRATA_12;
+
if (priv->errata)
dev_info(dev, "enabled errata workarounds, flags: 0x%x\n",
priv->errata);
@@ -2154,8 +2159,15 @@
/* Set up checksumming */
if (CHECKSUM_PARTIAL == skb->ip_summed) {
fcb = gfar_add_fcb(skb);
- lstatus |= BD_LFLAG(TXBD_TOE);
- gfar_tx_checksum(skb, fcb);
+ /* as specified by errata */
+ if (unlikely(gfar_has_errata(priv, GFAR_ERRATA_12)
+ && ((unsigned long)fcb % 0x20) > 0x18)) {
+ __skb_pull(skb, GMAC_FCB_LEN);
+ skb_checksum_help(skb);
+ } else {
+ lstatus |= BD_LFLAG(TXBD_TOE);
+ gfar_tx_checksum(skb, fcb);
+ }
}
if (vlan_tx_tag_present(skb)) {
diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index 54de413..ec5d595 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -1039,6 +1039,7 @@
GFAR_ERRATA_74 = 0x01,
GFAR_ERRATA_76 = 0x02,
GFAR_ERRATA_A002 = 0x04,
+ GFAR_ERRATA_12 = 0x08, /* a.k.a errata eTSEC49 */
};
/* Struct stolen almost completely (and shamelessly) from the FCC enet source