Currently for fixed-link the MAC driver decides whether to use the
link status auto-negotiation or not.
Unfortunately the auto-negotiation may not work when expected by
the MAC driver. Sebastien Rannou explains:
<< Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's
a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with
inband status) is connected to the switch through QSGMII, and in this context
we are on the media side of the PHY. >>
https://lkml.org/lkml/2015/7/10/206
This patch introduces the new boolean property 'autoneg' that allows
the user to request the auto-negotiation explicitly.
Signed-off-by: Stas Sergeev <s...@users.sourceforge.net>
CC: Rob Herring <robh...@kernel.org>
CC: Pawel Moll <pawel.m...@arm.com>
CC: Mark Rutland <mark.rutl...@arm.com>
CC: Ian Campbell <ijc+devicet...@hellion.org.uk>
CC: Kumar Gala <ga...@codeaurora.org>
CC: Florian Fainelli <f.faine...@gmail.com>
CC: Grant Likely <grant.lik...@linaro.org>
CC: devicet...@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: net...@vger.kernel.org
---
.../devicetree/bindings/net/fixed-link.txt | 6 +++++-
drivers/of/of_mdio.c | 23 ++++++++++++++++++++--
include/linux/of_mdio.h | 5 +++++
3 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/fixed-link.txt
b/Documentation/devicetree/bindings/net/fixed-link.txt
index 82bf7e0..e2959a8 100644
--- a/Documentation/devicetree/bindings/net/fixed-link.txt
+++ b/Documentation/devicetree/bindings/net/fixed-link.txt
@@ -9,8 +9,12 @@ Such a fixed link situation is described by creating a
'fixed-link'
sub-node of the Ethernet MAC device node, with the following
properties:
+* 'autoneg' (boolean, optional), to enable the auto-negotiation of link
+ state. Auto-negotiation is MII protocol, HW and driver-specific and is
+ not supported in many cases, so use it only when you know what you do.
* 'speed' (integer, mandatory), to indicate the link speed. Accepted
- values are 10, 100 and 1000
+ values are 10, 100 and 1000. If the auto-negotiation is enabled,
+ 'speed' may not be set. It will then be auto-negotiated, if possible.
* 'full-duplex' (boolean, optional), to indicate that full duplex is
used. When absent, half duplex is assumed.
* 'pause' (boolean, optional), to indicate that pause should be
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 1bd4305..12b2ede 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -280,6 +280,22 @@ bool of_phy_is_fixed_link(struct device_node *np)
}
EXPORT_SYMBOL(of_phy_is_fixed_link);
+bool of_phy_is_autoneg_link(struct device_node *np)
+{
+ struct device_node *dn;
+ bool ret;
+
+ dn = of_get_child_by_name(np, "fixed-link");
+ if (!dn)
+ return false;
+
+ ret = of_property_read_bool(dn, "autoneg");
+
+ of_node_put(dn);
+ return ret;
+}
+EXPORT_SYMBOL(of_phy_is_autoneg_link);
+
int of_phy_register_fixed_link(struct device_node *np)
{
struct fixed_phy_status status = {};
@@ -291,10 +307,13 @@ int of_phy_register_fixed_link(struct device_node *np)
/* New binding */
fixed_link_node = of_get_child_by_name(np, "fixed-link");
if (fixed_link_node) {
- status.link = 1;
+ bool autoneg = of_property_read_bool(fixed_link_node,
+ "autoneg");
+ status.link = !autoneg;
status.duplex = of_property_read_bool(fixed_link_node,
"full-duplex");
- if (of_property_read_u32(fixed_link_node, "speed",
&status.speed))
+ if (of_property_read_u32(fixed_link_node, "speed",
+ &status.speed) != 0 && !autoneg)
return -EINVAL;
status.pause = of_property_read_bool(fixed_link_node, "pause");
status.asym_pause = of_property_read_bool(fixed_link_node,
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index d449018..647f348 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -65,6 +65,7 @@ static inline struct mii_bus *of_mdio_find_bus(struct
device_node *mdio_np)
#if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)
extern int of_phy_register_fixed_link(struct device_node *np);
extern bool of_phy_is_fixed_link(struct device_node *np);
+extern bool of_phy_is_autoneg_link(struct device_node *np);
#else
static inline int of_phy_register_fixed_link(struct device_node *np)
{
@@ -74,6 +75,10 @@ static inline bool of_phy_is_fixed_link(struct device_node
*np)
{
return false;
}
+static inline bool of_phy_is_autoneg_link(struct device_node *np)
+{
+ return false;
+}
#endif
--
1.9.1
--
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