[PATCH 3.19 025/177] sh_eth: Fix lost MAC address on kexec

Greg Kroah-Hartman
2015-03-16T15:54:44Z

From: Geert Uytterhoeven <geert+renesas@glider.be>

[ Upstream commit a14c7d15ca91b444e77df08b916befdce77562ab ]

Commit 740c7f31c094703c ("sh_eth: Ensure DMA engines are stopped before
freeing buffers") added a call to sh_eth_reset() to the
sh_eth_set_ringparam() and sh_eth_close() paths.

However, setting the software reset bit(s) in the EDMR register resets
the MAC Address Registers to zero. Hence after kexec, the new kernel
doesn't detect a valid MAC address and assigns a random MAC address,
breaking DHCP.

Set the MAC address again after the reset in sh_eth_dev_exit() to fix
this.

Tested on r8a7740/armadillo (GETHER) and r8a7791/koelsch (FAST_RCAR).

Fixes: 740c7f31c094703c ("sh_eth: Ensure DMA engines are stopped before freeing buffers")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/renesas/sh_eth.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1392,6 +1392,9 @@ static void sh_eth_dev_exit(struct net_d
msleep(2); /* max frame time at 10 Mbps < 1250 us */
sh_eth_get_stats(ndev);
sh_eth_reset(ndev);
+
+ /* Set MAC address again */
+ update_mac_address(ndev);
}

/* free Tx skb function */