[U-Boot] [RFC PATCH 8/8] net: e1000 enable multicast reception

[Chris Packham]

IPv6 neighbor discovery uses various multicast addresses to send the
request and receive the response. For neighbor discovery to work
properly in U-boot the Ethernet device needs to support joining/leaving
various L2 multicast groups or it needs to support multicast/promiscuous
mode. For the sake of simplicity the latter approach has been taken. The
e1000 hardware has slightly finer grained control in that it is possible
to enable support for multicast-promiscuous mode separately from unicast
so the extra traffic received is less.

Signed-off-by: Chris Packham <judge.packham at gmail.com>
---
Drivers that support multicast reception have it enabled/disabled with
CONFIG_MCAST_TFTP. It wouldn't be too hard to create a separate
CONFIG_MCAST that is selected by enabling CONFIG_MCAST_TFTP or
CONFIG_NET6.

 drivers/net/e1000.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/e1000.c b/drivers/net/e1000.c
index 2ba03ed..e5b00a4 100644
--- a/drivers/net/e1000.c
+++ b/drivers/net/e1000.c
@@ -5090,6 +5090,11 @@ e1000_setup_rctl(struct e1000_hw *hw)
 	rctl &= ~(E1000_RCTL_SZ_4096);
 		rctl |= E1000_RCTL_SZ_2048;
 		rctl &= ~(E1000_RCTL_BSEX | E1000_RCTL_LPE);
+
+#ifdef CONFIG_CMD_NET6
+	rctl |= E1000_RCTL_MPE;
+#endif
+
 	E1000_WRITE_REG(hw, RCTL, rctl);
 }
 
-- 
2.5.3