net: phy: realtek: restore RTL8211F RGMII delays on resume

RTL8211F and RTL8211F-VD both use rtl8211f_config_rgmii_delay() during
initialization and share rtl821x_resume(). The RTL8211F-VD loses its
RGMII TX and RX delay enable bits across a software power-down, but the
shared resume path only clears BMCR_PDOWN and waits for the receive clock
to stabilize.

On a BeagleV Ahead configured for rgmii-id, carrier and the negotiated
speed return after an interface close/open, but the receive path does not
work. At 100 Mbit/s no frames were received. At 1000 Mbit/s all 11
observed frames had CRC errors.

Reapply the RGMII delay configuration after the existing resume delay.

Tested on a BeagleV Ahead with an RTL8211F-VD at 100 and 1000 Mbit/s,
including close/open without a link partner.

Fixes: bb726b753f75 ("net: phy: realtek: add support for RTL8211F(D)(I)-VD-CG")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Link: https://patch.msgid.link/20261015045001.83986-1-kmehltretter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions