linux-stable.git/drivers/net/phy/microchip.c, branch linux-5.4.y Linux kernel stable tree net: phy: microchip: limit 100M workaround to link-down events on LAN88xx 2025-07-17T16:25:04+00:00 Oleksij Rempel o.rempel@pengutronix.de 2025-07-09T13:07:53+00:00 7c0beeab3a3003811a54e44abfe1bfe576f020ff [ Upstream commit dd4360c0e8504f2f7639c7f5d07c93cfd6a98333 ] Restrict the 100Mbit forced-mode workaround to link-down transitions only, to prevent repeated link reset cycles in certain configurations. The workaround was originally introduced to improve signal reliability when switching cables between long and short distances. It temporarily forces the PHY into 10 Mbps before returning to 100 Mbps. However, when used with autonegotiating link partners (e.g., Intel i350), executing this workaround on every link change can confuse the partner and cause constant renegotiation loops. This results in repeated link down/up transitions and the PHY never reaching a stable state. Limit the workaround to only run during the PHY_NOLINK state. This ensures it is triggered only once per link drop, avoiding disruptive toggling while still preserving its intended effect. Note: I am not able to reproduce the original issue that this workaround addresses. I can only confirm that 100 Mbit mode works correctly in my test setup. Based on code inspection, I assume the workaround aims to reset some internal state machine or signal block by toggling speeds. However, a PHY reset is already performed earlier in the function via phy_init_hw(), which may achieve a similar effect. Without a reproducer, I conservatively keep the workaround but restrict its conditions. Fixes: e57cf3639c32 ("net: lan78xx: fix accessing the LAN7800's internal phy specific registers from the MAC driver") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://patch.msgid.link/20250709130753.3994461-3-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dd4360c0e8504f2f7639c7f5d07c93cfd6a98333 ]

Restrict the 100Mbit forced-mode workaround to link-down transitions
only, to prevent repeated link reset cycles in certain configurations.

The workaround was originally introduced to improve signal reliability
when switching cables between long and short distances. It temporarily
forces the PHY into 10 Mbps before returning to 100 Mbps.

However, when used with autonegotiating link partners (e.g., Intel i350),
executing this workaround on every link change can confuse the partner
and cause constant renegotiation loops. This results in repeated link
down/up transitions and the PHY never reaching a stable state.

Limit the workaround to only run during the PHY_NOLINK state. This ensures
it is triggered only once per link drop, avoiding disruptive toggling
while still preserving its intended effect.

Note: I am not able to reproduce the original issue that this workaround
addresses. I can only confirm that 100 Mbit mode works correctly in my
test setup. Based on code inspection, I assume the workaround aims to
reset some internal state machine or signal block by toggling speeds.
However, a PHY reset is already performed earlier in the function via
phy_init_hw(), which may achieve a similar effect. Without a reproducer,
I conservatively keep the workaround but restrict its conditions.

Fixes: e57cf3639c32 ("net: lan78xx: fix accessing the LAN7800's internal phy specific registers from the MAC driver")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250709130753.3994461-3-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: lan78xx: fix accessing the LAN7800's internal phy specific registers from the MAC driver 2023-03-17T07:32:51+00:00 Yuiko Oshino yuiko.oshino@microchip.com 2023-03-01T15:43:07+00:00 8018aa0863d64ee7c14997a1d8e5f112ee95f447 [ Upstream commit e57cf3639c323eeed05d3725fd82f91b349adca8 ] Move the LAN7800 internal phy (phy ID 0x0007c132) specific register accesses to the phy driver (microchip.c). Fix the error reported by Enguerrand de Ribaucourt in December 2022, "Some operations during the cable switch workaround modify the register LAN88XX_INT_MASK of the PHY. However, this register is specific to the LAN8835 PHY. For instance, if a DP8322I PHY is connected to the LAN7801, that register (0x19), corresponds to the LED and MAC address configuration, resulting in unapropriate behavior." I did not test with the DP8322I PHY, but I tested with an EVB-LAN7800 with the internal PHY. Fixes: 14437e3fa284 ("lan78xx: workaround of forced 100 Full/Half duplex mode error") Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20230301154307.30438-1-yuiko.oshino@microchip.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e57cf3639c323eeed05d3725fd82f91b349adca8 ]

Move the LAN7800 internal phy (phy ID  0x0007c132) specific register
accesses to the phy driver (microchip.c).

Fix the error reported by Enguerrand de Ribaucourt in December 2022,
"Some operations during the cable switch workaround modify the register
LAN88XX_INT_MASK of the PHY. However, this register is specific to the
LAN8835 PHY. For instance, if a DP8322I PHY is connected to the LAN7801,
that register (0x19), corresponds to the LED and MAC address
configuration, resulting in unapropriate behavior."

I did not test with the DP8322I PHY, but I tested with an EVB-LAN7800
with the internal PHY.

Fixes: 14437e3fa284 ("lan78xx: workaround of forced 100 Full/Half duplex mode error")
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230301154307.30438-1-yuiko.oshino@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: phy: remove calls to genphy_config_init 2019-08-17T19:34:50+00:00 Heiner Kallweit hkallweit1@gmail.com 2019-08-17T10:29:25+00:00 c227ce4423855bddb41a05ad25a93f13b96c89bd Supported PHY features are either auto-detected or explicitly set. In both cases calling genphy_config_init isn't needed. All that genphy_config_init does is removing features that are set as supported but can't be auto-detected. Basically it duplicates the code in genphy_read_abilities. Therefore remove such calls from all PHY drivers. v2: - remove call also from new adin PHY driver v3: - pass NULL as config_init function pointer for dp83848 Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Supported PHY features are either auto-detected or explicitly set.
In both cases calling genphy_config_init isn't needed. All that
genphy_config_init does is removing features that are set as
supported but can't be auto-detected. Basically it duplicates the
code in genphy_read_abilities. Therefore remove such calls from
all PHY drivers.

v2:
- remove call also from new adin PHY driver
v3:
- pass NULL as config_init function pointer for dp83848

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: switch drivers to use dynamic feature detection 2019-04-16T00:19:54+00:00 Heiner Kallweit hkallweit1@gmail.com 2019-04-12T18:47:03+00:00 dcdecdcfe1fc39ded8590aed2fe84d62f14b2392 Recently genphy_read_abilities() has been added that dynamically detects clause 22 PHY abilities. I *think* this detection should work with all supported PHY's, at least for the ones with basic features sets, i.e. PHY_BASIC_FEATURES and PHY_GBIT_FEATURES. So let's remove setting these features explicitly and rely on phylib feature detection. I don't have access to most of these PHY's, therefore I'd appreciate regression testing. v2: - make the feature constant a comment so that readers know which features are supported by the respective PHY Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
Recently genphy_read_abilities() has been added that dynamically detects
clause 22 PHY abilities. I *think* this detection should work with all
supported PHY's, at least for the ones with basic features sets, i.e.
PHY_BASIC_FEATURES and PHY_GBIT_FEATURES. So let's remove setting these
features explicitly and rely on phylib feature detection.

I don't have access to most of these PHY's, therefore I'd appreciate
regression testing.

v2:
- make the feature constant a comment so that readers know which
  features are supported by the respective PHY

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: Convert some PHY and MDIO driver files to SPDX headers 2019-01-23T04:53:08+00:00 Andrew Lunn andrew@lunn.ch 2019-01-21T18:05:50+00:00 a2443fd1a54d6ae787157794a2920dd61f50f7f1 Where the license text and the MODULE_LICENSE() value agree, convert to using an SPDX header, removing the license text. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
Where the license text and the MODULE_LICENSE() value agree, convert
to using an SPDX header, removing the license text.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: remove flag PHY_HAS_INTERRUPT from driver configs 2018-11-11T17:36:56+00:00 Heiner Kallweit hkallweit1@gmail.com 2018-11-09T17:17:22+00:00 a4307c0ec66131e722a8fa0f1da09646c46ee924 Now that flag PHY_HAS_INTERRUPT has been replaced with a check for callbacks config_intr and ack_interrupt, we can remove setting this flag from all driver configs. Last but not least remove flag PHY_HAS_INTERRUPT completely. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
Now that flag PHY_HAS_INTERRUPT has been replaced with a check for
callbacks config_intr and ack_interrupt, we can remove setting this
flag from all driver configs.
Last but not least remove flag PHY_HAS_INTERRUPT completely.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: Add phydev_warn() 2018-10-02T05:55:35+00:00 Andrew Lunn andrew@lunn.ch 2018-09-29T21:04:10+00:00 ab2a605fa621ecf4ec26603a237822f7772cfa28 Not all new style LINK_MODE bits can be converted into old style SUPPORTED bits. We need to warn when such a conversion is attempted. Add a helper for this. Convert all pr_warn() calls to phydev_warn() where possible. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Not all new style LINK_MODE bits can be converted into old style
SUPPORTED bits. We need to warn when such a conversion is attempted.
Add a helper for this.

Convert all pr_warn() calls to phydev_warn() where possible.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-21T20:32:48+00:00 David S. Miller davem@davemloft.net 2018-04-21T20:31:52+00:00 e0ada51db907ed2db5d46ad7ff86a8b5df68e59b Conflicts were simple overlapping changes in microchip driver. Signed-off-by: David S. Miller <davem@davemloft.net> 
Conflicts were simple overlapping changes in microchip
driver.

Signed-off-by: David S. Miller <davem@davemloft.net>
lan78xx: Read LED states from Device Tree 2018-04-20T15:39:09+00:00 Phil Elwell phil@raspberrypi.org 2018-04-19T16:59:39+00:00 1827b0678863bc97a1653fdf5308762b2aefcd56 Add support for DT property "microchip,led-modes", a vector of zero to four cells (u32s) in the range 0-15, each of which sets the mode for one of the LEDs. Some possible values are: 0=link/activity 1=link1000/activity 2=link100/activity 3=link10/activity 4=link100/1000/activity 5=link10/1000/activity 6=link10/100/activity 14=off 15=on These values are given symbolic constants in a dt-bindings header. Also use the presence of the DT property to indicate that the LEDs should be enabled - necessary in the event that no valid OTP or EEPROM is available. Signed-off-by: Phil Elwell <phil@raspberrypi.org> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add support for DT property "microchip,led-modes", a vector of zero
to four cells (u32s) in the range 0-15, each of which sets the mode
for one of the LEDs. Some possible values are:

    0=link/activity          1=link1000/activity
    2=link100/activity       3=link10/activity
    4=link100/1000/activity  5=link10/1000/activity
    6=link10/100/activity    14=off    15=on

These values are given symbolic constants in a dt-bindings header.

Also use the presence of the DT property to indicate that the
LEDs should be enabled - necessary in the event that no valid OTP
or EEPROM is available.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
lan78xx: PHY DSP registers initialization to address EEE link drop issues with long cables 2018-04-13T01:46:10+00:00 Raghuram Chary J raghuramchary.jallipalli@microchip.com 2018-04-11T15:06:36+00:00 1c2734b31d72316e3faaad88c0c9c46fa92a4b20 The patch is to configure DSP registers of PHY device to handle Gbe-EEE failures with >40m cable length. Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver") Signed-off-by: Raghuram Chary J <raghuramchary.jallipalli@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The patch is to configure DSP registers of PHY device
to handle Gbe-EEE failures with >40m cable length.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Raghuram Chary J <raghuramchary.jallipalli@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>