usb_phy_root...loc_usb3_phy(9)

✨ NAME ✨

usb_phy_roothub_alloc_usb3_phy — the one that allocs the roothub 💅

okay so real talk, this is from the Kernel API Manual, and it's literally just one little function that goes and sets up your USB PHY roothub for you. bestie, it's giving "small but mighty." 🎀

---

🌸 SYNOPSIS 🌸

struct usb_phy_roothub * usb_phy_roothub_alloc_usb3_phy (struct device *dev );

that's it. that's the whole vibe. one function, one argument, no cap. ✨

---

🦋 ARGUMENTS 🦋

• dev — the device of the host controller. like, the host controller device, okay? hand it over and let the function cook. 🍓

---

💖 DESCRIPTION 💖

So what it does: it allocates the usb phy roothub — but only if the host is using a generic usb3-phy. iykyk. if your host isn't on that generic usb3-phy situation, this function's just gonna be like "not my problem" and hand you back NULL (more on that below 👀). literally obsessed with how straightforward that is.

---

🔥 RETURN 🔥

Here's the vibe check on what comes back:

• On success → a pointer to the usb_phy_roothub. slay, you got your roothub. 👑
• Otherwise → NULL if there's no use of a usb3 phy, or -ENOMEM if it ran out of memory. 😭 that second one is the "it's not you, it's the allocator" energy.

ok but fr fr, watch for that -ENOMEM — if memory's tapped out, no amount of main character energy is saving that call. 💀

---

🌈 SEE ALSO 🌈

• Kernel file ./drivers/usb/core/phy.c
• usb_phy_roothub_notify_connect(9)
• usb_phy_roothub_notify_disconnect(9)

go read those next, bestie, they're the rest of the roothub lore 🫶

---

and that's the whole page! signed, sealed, delivered from ./drivers/usb/core, dated October 2026, version usb_phy_root...loc_usb3_phy(9) — mwah 💋🧚💜