[PATCH 4.9 189/218] net: stmmac: Fix unset max_speed difference between DT and non-DT platforms

Greg Kroah-Hartman
2022-04-18T14:23:23Z

From: Chen-Yu Tsai <wens@csie.org>

[ Upstream commit c21cabb0fd0b54b8b54235fc1ecfe1195a23bcb2 ]

In commit 9cbadf094d9d ("net: stmmac: support max-speed device tree
property"), when DT platforms don't set "max-speed", max_speed is set to
-1; for non-DT platforms, it stays the default 0.

Prior to commit eeef2f6b9f6e ("net: stmmac: Start adding phylink support"),
the check for a valid max_speed setting was to check if it was greater
than zero. This commit got it right, but subsequent patches just checked
for non-zero, which is incorrect for DT platforms.

In commit 92c3807b9ac3 ("net: stmmac: convert to phylink_get_linkmodes()")
the conversion switched completely to checking for non-zero value as a
valid value, which caused 1000base-T to stop getting advertised by
default.

Instead of trying to fix all the checks, simply leave max_speed alone if
DT property parsing fails.

Fixes: 9cbadf094d9d ("net: stmmac: support max-speed device tree property")
Fixes: 92c3807b9ac3 ("net: stmmac: convert to phylink_get_linkmodes()")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220331184832.16316-1-wens@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 2019e163e0e9..cbdd0deb7c56 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -221,8 +221,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
plat->interface = of_get_phy_mode(np);

/* Get max speed of operation from device tree */
- if (of_property_read_u32(np, "max-speed", &plat->max_speed))
- plat->max_speed = -1;
+ of_property_read_u32(np, "max-speed", &plat->max_speed);

plat->bus_id = of_alias_get_id(np, "ethernet");
if (plat->bus_id < 0)
--
2.35.1