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 Assisted-by: LLM Signed-off-by: Karl Mehltretter --- v2: - Move the shared RTL8211F/RTL8211F-VD resume-path explanation earlier. - Add Andrew's Reviewed-by. v1: https://lore.kernel.org/netdev/20261014033659.95196-1-kmehltretter@gmail.com/ Hardware test results on BeagleV Ahead (RTL8211F-VD, rgmii-id): baseline patched 100 Mbit/s close/open RX silent pass 1000 Mbit/s close/open 11/11 CRC errors pass no-link close/open, reconnect 15/15 CRC errors pass The patched kernel also passed bidirectional 1 MiB SHA-256 transfers at 100 and 1000 Mbit/s and eight consecutive 1000 Mbit/s close/open cycles, all without RX CRC errors. An s2idle suspend/resume test passed on both kernels and did not reproduce the bug. Testing on an RTL8211F (non-VD) would be welcome. Built with ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- LLVM=1. drivers/net/phy/realtek/realtek_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/phy/realtek/realtek_main.c b/drivers/net/phy/realtek/realtek_main.c index 177b62a7b2d16..c867e5213216b 100644 --- a/drivers/net/phy/realtek/realtek_main.c +++ b/drivers/net/phy/realtek/realtek_main.c @@ -1375,7 +1375,7 @@ static int rtl821x_resume(struct phy_device *phydev) msleep(20); - return 0; + return rtl8211f_config_rgmii_delay(phydev); } static int rtl8211f_resume(struct phy_device *phydev) -- 2.39.5 (Apple Git-154)