[PATCH 4.1 25/29] mvneta: use inband status only when explicitly enabled

From: Greg Kroah-Hartman
Date: Thu Oct 01 2015 - 05:36:59 EST


4.1-stable review patch. If anyone has any objections, please let me know.

------------------

From: Stas Sergeev <stsp@xxxxxxx>

[ Upstream commit f8af8e6eb95093d5ce5ebcc52bd1929b0433e172 in net-next tree,
will be pushed to Linus very soon. ]

The commit 898b2970e2c9 ("mvneta: implement SGMII-based in-band link state
signaling") implemented the link parameters auto-negotiation unconditionally.
Unfortunately it appears that some HW that implements SGMII protocol,
doesn't generate the inband status, so it is not possible to auto-negotiate
anything with such HW.

This patch enables the auto-negotiation only if explicitly requested with
the 'managed' DT property.

This patch fixes the following regression:
https://lkml.org/lkml/2015/7/8/865

Signed-off-by: Stas Sergeev <stsp@xxxxxxxxxxxxxxxxxxxxx>

CC: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
CC: netdev@xxxxxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/marvell/mvneta.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3029,8 +3029,8 @@ static int mvneta_probe(struct platform_
const char *dt_mac_addr;
char hw_mac_addr[ETH_ALEN];
const char *mac_from;
+ const char *managed;
int phy_mode;
- int fixed_phy = 0;
int err;

/* Our multiqueue support is not complete, so for now, only
@@ -3064,7 +3064,6 @@ static int mvneta_probe(struct platform_
dev_err(&pdev->dev, "cannot register fixed PHY\n");
goto err_free_irq;
}
- fixed_phy = 1;

/* In the case of a fixed PHY, the DT node associated
* to the PHY is the Ethernet MAC DT node.
@@ -3088,8 +3087,10 @@ static int mvneta_probe(struct platform_
pp = netdev_priv(dev);
pp->phy_node = phy_node;
pp->phy_interface = phy_mode;
- pp->use_inband_status = (phy_mode == PHY_INTERFACE_MODE_SGMII) &&
- fixed_phy;
+
+ err = of_property_read_string(dn, "managed", &managed);
+ pp->use_inband_status = (err == 0 &&
+ strcmp(managed, "in-band-status") == 0);

pp->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pp->clk)) {


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