Re: [PATCH v2 2/2] usb: ehci-pci: Set has_hostpc for TDI EHCI on Intel CE5300

[sashiko-bot@kernel.org]

> From: Joseph Telaak <joseph@telaak.dev>
> 
> The TransDimension EHCI core in the Intel CE5300 SoCs (192e:0101,
> revision >= 6) has the Moorestown-style register extensions: host
> mode is selected in USBMODE_EX rather than USBMODE, and the port speed
> is reported in HOSTPC.
> 
> Without has_hostpc, ehci_reset() never programs USBMODE_EX, so the
> core stays in idle mode: USBMODE_EX reads back 0, USBCMD.RS never
> sets and no device is ever reported as connected, even though the
> probe itself succeeds. With it, USBMODE_EX reads back 0x23 and
> devices enumerate.
> 
> USBMODE itself always reads back 0 on this core, so
> tdi_in_host_mode() would report a running controller as not in host
> mode and ehci_halt() would return without stopping it. Add
> has_usbmode_ex so that, for this core only, tdi_in_host_mode() reads
> host mode back from USBMODE_EX. ChipIdea also sets has_hostpc but
> keeps host mode in USBMODE, so it is unaffected.
> 
> Intel's CE5300 BSP sets has_hostpc for device 0x0101, revision >= 6.
> 
> Tested on a Control4 EA-3 (Intel Atom CE5310) with v7.3-rc6: a
> full-speed CP2104 USB-UART bridge (10c4:ea60) and a high-speed USB
> flash drive (0781:5575) enumerate with this change, and
> ehci_shutdown() leaves the controller halted (USBCMD.RS clear,
> USBSTS.HCHalted set); without the USBMODE_EX check it stays running.
> 
> Assisted-by: LLM
> Signed-off-by: Joseph Telaak <joseph@telaak.dev>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261027-ehci-ce5300-hostpc-v2-0-375e9d362d74@telaak.dev?part=2