[PATCH 5.9 156/255] lan743x: correctly handle chips with internal PHY

Greg Kroah-Hartman
2020-11-17T13:39:26Z

From: Sven Van Asbroeck <thesven73@gmail.com>

[ Upstream commit 902a66e08ceaadb9a7a1ab3a4f3af611cd1d8cba ]

Commit 6f197fb63850 ("lan743x: Added fixed link and RGMII support")
assumes that chips with an internal PHY will never have a devicetree
entry. This is incorrect: even for these chips, a devicetree entry
can be useful e.g. to pass the mac address from bootloader to chip:

&pcie {
status = "okay";

host@0 {
reg = <0 0 0 0 0>;

#address-cells = <3>;
#size-cells = <2>;

lan7430: ethernet@0 {
/* LAN7430 with internal PHY */
compatible = "microchip,lan743x";
status = "okay";
reg = <0 0 0 0 0>;
/* filled in by bootloader */
local-mac-address = [00 00 00 00 00 00];
};
};
};

If a devicetree entry is present, the driver will not attach the chip
to its internal phy, and the chip will be non-operational.

Fix by tweaking the phy connection algorithm:
- first try to connect to a phy specified in the devicetree
(could be 'real' phy, or just a 'fixed-link')
- if that doesn't succeed, try to connect to an internal phy, even
if the chip has a devnode

Tested on a LAN7430 with internal PHY. I cannot test a device using
fixed-link, as I do not have access to one.

Fixes: 6f197fb63850 ("lan743x: Added fixed link and RGMII support")
Tested-by: Sven Van Asbroeck <thesven73@gmail.com> # lan7430
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Link: https://lore.kernel.org/r/20201108171224.23829-1-TheSven73@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/microchip/lan743x_main.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index de93cc6ebc1ac..be58a941965b1 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1027,9 +1027,9 @@ static int lan743x_phy_open(struct lan743x_adapter *adapter)

netdev = adapter->netdev;
phynode = of_node_get(adapter->pdev->dev.of_node);
- adapter->phy_mode = PHY_INTERFACE_MODE_GMII;

if (phynode) {
+ /* try devicetree phy, or fixed link */
of_get_phy_mode(phynode, &adapter->phy_mode);

if (of_phy_is_fixed_link(phynode)) {
@@ -1045,13 +1045,15 @@ static int lan743x_phy_open(struct lan743x_adapter *adapter)
lan743x_phy_link_status_change, 0,
adapter->phy_mode);
of_node_put(phynode);
- if (!phydev)
- goto return_error;
- } else {
+ }
+
+ if (!phydev) {
+ /* try internal phy */
phydev = phy_find_first(adapter->mdiobus);
if (!phydev)
goto return_error;

+ adapter->phy_mode = PHY_INTERFACE_MODE_GMII;
ret = phy_connect_direct(netdev, phydev,
lan743x_phy_link_status_change,
adapter->phy_mode);
--
2.27.0