Re: [PATCH v2 2/2] usb: hub: Retry SuperSpeed for a device stuck on its USB 2.0 peer

[sashiko-bot@kernel.org]

> From: Arun Iyengar <aiyengar1990@gmail.com>
> 
> A SuperSpeed device looks for a SuperSpeed link first when it sees
> VBUS, and connects at high speed when the link doesn't come up. It
> looks again only when VBUS is cycled or after a USB 2.0 bus reset.
> 
> When a connector's two halves belong to different host controllers,
> the USB 2.0 host can start first. On the Orange Pi 5 (RK3588S), whose
> USB 3 Type-A port has VBUS on from power-up, a USB 3 flash drive
> plugged in at boot was reset by the EHCI about 10 ms before the
> SuperSpeed-only xHCI registered, so it came up at 480 Mb/s on the EHCI
> in every one of 6 boots, while plugging it in after boot gave
> 5 Gb/s. It stays at high speed until it is unplugged.
> 
> When a SuperSpeed root hub with ports paired through a connector to a
> [ ... ]
> to its SuperSpeed half. The work runs on the freezable hub_wq, holds a
> runtime PM reference on the SuperSpeed hub and is cancelled when the
> hub is quiesced.
> 
> Signed-off-by: Arun Iyengar <aiyengar1990@gmail.com>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261112-usb-port-pairing-v2-0-45f5a1a29f1f@gmail.com?part=2