The sh_eth_close() resets the MAC and then calls phy_stop() so that mdio read access result is incorrect without any error according to kernel trace like below: ifconfig-216 [003] .n.. 109.133124: mdio_access: ee700000.ethernet-ffffffff read phy:0x01 reg:0x00 val:0xffff According to the hardware manual, the RMII mode should be set to 1 before operation the Ethernet MAC. However, the previous code was not set to 1 after the driver issued the soft_reset in sh_eth_dev_exit() so that the mdio read access result seemed incorrect. To fix the issue, this patch adds a condition and set the RMII mode register in sh_eth_dev_exit() for R-Car Gen2 and RZ/A1 SoCs. Note that when I have tried to move the sh_eth_dev_exit() calling after phy_stop() on sh_eth_close(), but it gets worse (kernel panic happened and it seems that a register is accessed while the clock is off). Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> --- Changes from v1 (https://patchwork.kernel.org/patch/10944265/): - Revise the subject, commit log and the comment of the code. - Move the RMII setting to right after soft_reset. drivers/net/ethernet/renesas/sh_eth.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index 6354f19..7ba35a0 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1594,6 +1594,10 @@ static void sh_eth_dev_exit(struct net_device *ndev) sh_eth_get_stats(ndev); mdp->cd->soft_reset(ndev); + /* Set the RMII mode again if required */ + if (mdp->cd->rmiimode) + sh_eth_write(ndev, 0x1, RMIIMODE); + /* Set MAC address again */ update_mac_address(ndev); } -- 2.7.4
