[PATCH 2/6] usb: xhci: Set up endpoints for the first 2 interfaces

[Marek Vasut]

On 2/25/24 4:28 PM, Janne Grunau wrote:
> 
> 
> On Wed, Feb 21, 2024, at 13:39, Marek Vasut wrote:
>> On 2/21/24 08:25, Janne Grunau via B4 Relay wrote:
>>> From: Janne Grunau <j at jannau.net>
>>>
>>> Apple USB keyboards carry the HID keyboard boot protocol on the second
>>> interface. Using the second interface in the USB keyboard driver does
>>> not work since the xhci has not allocated a transfer ring.
>>
>> So, what does this patch do ? That is not clear from the commit message.
> 
> rewritten for v2:
> | usb: xhci: Set up endpoints for the first 2 interfaces
> |
> | The xhci driver currently only does the necessary initialization for
> | endpoints found in the first interface descriptor. Apple USB keyboards
> | (released 2021) use the second interface descriptor for the HID keyboard
> | boot protocol. To allow USB drivers to use endpoints from other
> | interface descriptors the xhci driver needs to ensure these endpoints
> | are initialized as well.
> | Use USB_MAX_ACTIVE_INTERFACES to control how many interface descriptors
> | are initialized and useable. Currently defined to 2 as that is enough to
> | make the Apple keyboard usable.

Would it make sense to make this a tunable Kconfig option ?