net: phy: dp83867: restore LED configuration after a soft reset

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The LED configuration lives in LEDCR1 (the per-LED function nibble) and
LEDCR2 (per-LED driver enable/value and polarity). The driver programs it
through the LED class callbacks -- dp83867_led_brightness_set(),
dp83867_led_hw_control_set() and dp83867_led_polarity_set() -- either once
from device tree at probe, or at runtime from sysfs and the netdev trigger.

dp83867_phy_reset(), the .soft_reset callback, issues a global software
reset (CTRL SW_RESET), which the datasheet defines as resetting all
registers, including the extended registers, to their defaults.
phy_init_hw() runs .soft_reset before .config_init on every attach and
resume -- phy_attach_direct(), mdio_bus_phy_resume() and MAC drivers -- so
the LED configuration is wiped from the first attach onward and never
restored. A device-tree polarity is lost, a manually driven LED goes dark,
and an LED offloaded to the netdev trigger whose link stays down after a
resume keeps the reset-default function until the next link event.

Shadow what the LED callbacks program, as a value and a written-bits mask
per register, and replay it from config_init(), which runs right after the
soft reset. Only bits the driver actually set are restored.

The callbacks run under phydev->lock, but config_init() must not take it:
the cable-test abort path in phy_state_machine() already holds phydev->lock
when it reaches phy_init_hw(), so config_init() taking it would deadlock.
Serialize the shadow and its replay with a dedicated lock instead.

Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Link: https://patch.msgid.link/20260908235740.120112-1-donggeunyoo.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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This commit is contained in:

Donggeun Yoo 2026-09-09 08:57:40 +09:00 • committed by Jakub Kicinski

parent 1f20151408

commit 043777e948

1 changed files with 98 additions and 13 deletions

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drivers/net/phy/dp83867.c

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