[PATCH 5.10 59/77] net: nxp: lpc_eth.c: avoid hang when bringing interface down

Greg Kroah-Hartman
2021-11-01T09:37:17Z

From: Trevor Woerner <twoerner@gmail.com>

commit ace19b992436a257d9a793672e57abc28fe83e2e upstream.

A hard hang is observed whenever the ethernet interface is brought
down. If the PHY is stopped before the LPC core block is reset,
the SoC will hang. Comparing lpc_eth_close() and lpc_eth_open() I
re-arranged the ordering of the functions calls in lpc_eth_close() to
reset the hardware before stopping the PHY.
Fixes: b7370112f519 ("lpc32xx: Added ethernet driver")
Signed-off-by: Trevor Woerner <twoerner@gmail.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/nxp/lpc_eth.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/nxp/lpc_eth.c
+++ b/drivers/net/ethernet/nxp/lpc_eth.c
@@ -1015,9 +1015,6 @@ static int lpc_eth_close(struct net_devi
napi_disable(&pldat->napi);
netif_stop_queue(ndev);

- if (ndev->phydev)
- phy_stop(ndev->phydev);
-
spin_lock_irqsave(&pldat->lock, flags);
__lpc_eth_reset(pldat);
netif_carrier_off(ndev);
@@ -1025,6 +1022,8 @@ static int lpc_eth_close(struct net_devi
writel(0, LPC_ENET_MAC2(pldat->net_base));
spin_unlock_irqrestore(&pldat->lock, flags);

+ if (ndev->phydev)
+ phy_stop(ndev->phydev);
clk_disable_unprepare(pldat->clk);

return 0;