ytphy_read_ext(9)

💖 ytphy_read_ext(9) 💖

okay bestie, we're in the ytphy_read_ext(9) page in the Kernel API Manual, and this one is short, sweet, and lowkey iconic. It reads a PHY's extended register. That's the whole assignment, and it ate.

🌸 NAME 🌸

ytphy_read_ext — read a PHY's extended register. Exactly what it says on the tin, and the tin is cute.

✨ SYNOPSIS ✨

int ytphy_read_ext (struct phy_device *phydev , u16 regnum );

🫶 ARGUMENTS 🫶

• phydev — a pointer to a struct phy_device. It's the PHY device you're working with, bestie.
• regnum — register number to read. This is the extended-register address you want the tea from.

⚠️ NOTE ⚠️

Lock moment, fr fr: the caller must have taken the MDIO bus lock.

After that, it returns the value of regnum reg or negative error code. That's it — no extra lore, no cap.

👀 SEE ALSO 👀

The kernel file is ./drivers/net/phy/motorcomm.c, and here's the whole iconic friend group:

• ytphy_read_ext_with_lock(9), ytphy_write_ext(9), ytphy_write_ext_with_lock(9), ytphy_modify_ext(9), ytphy_modify_ext_with_lock(9), ytphy_get_wol(9), ytphy_set_wol(9)
• yt8521_read_page(9), yt8521_write_page(9), struct ytphy_cfg_reg_map(9), struct ytphy_ldo_vol_map(9), yt8521_probe(9), ytphy_utp_read_lpa(9)
• yt8521_adjust_status(9), yt8521_read_status_paged(9), yt8521_read_status(9), yt8521_modify_bmcr_paged(9), yt8521_modify_utp_fiber_bmcr(9), yt8521_soft_reset(9)
• yt8521_suspend(9), yt8521_resume(9), yt8521_config_init(9), yt8531_link_change_notify(9), yt8521_prepare_fiber_features(9), yt8521_fiber_setup_forced(9)
• ytphy_check_and_restart_aneg(9), yt8521_fiber_config_aneg(9), ytphy_setup_master_slave(9), ytphy_utp_config_advert(9), ytphy_utp_config_aneg(9)
• yt8521_config_aneg_paged(9), yt8521_config_aneg(9), yt8521_aneg_done_paged(9), yt8521_aneg_done(9), ytphy_utp_read_abilities(9)
• yt8521_get_features_paged(9), yt8521_get_features(9), yt8821_get_features(9), yt8821_get_rate_matching(9), yt8821_aneg_done(9), yt8821_serdes_init(9)
• yt8821_utp_init(9), yt8821_auto_sleep_config(9), yt8821_soft_reset(9), yt8821_config_init(9), yt8821_adjust_status(9), yt8821_update_interface(9)
• yt8821_read_status(9), yt8821_modify_utp_fiber_bmcr(9), yt8821_suspend(9), yt8821_resume(9)

sign-off time, bestie: from ./drivers/net/phy, October 2026 — this was ytphy_read_ext(9) 💅✨