sh_eth: Fix lost MAC address on kexec

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>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 4da8bd263997..654b48d1e61a 100644
--- 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_device *ndev)
         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 */