On Fri, Mar 22, 2024 at 09:17:08AM +0100, Heinrich Schuchardt wrote:
On 3/22/24 08:47, Janne Grunau via B4 Relay wrote:
From: Janne Grunau j@jannau.net
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 considered during endpoint initialisation. For now define it to 2 as that is sufficient for supporting the Apple keyboards.
Reviewed-by: Marek Vasut marex@denx.de Reviewed-by: Neal Gompa neal@gompa.dev Signed-off-by: Janne Grunau j@jannau.net
drivers/usb/host/xhci.c | 31 +++++++++++++++++++------------ include/usb.h | 6 ++++++ 2 files changed, 25 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 534c4b973f..741e186ee0 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -606,24 +606,28 @@ static int xhci_set_configuration(struct usb_device *udev) int slot_id = udev->slot_id; struct xhci_virt_device *virt_dev = ctrl->devs[slot_id]; struct usb_interface *ifdesc;
- unsigned int ifnum;
- unsigned int max_ifnum = min((unsigned int)USB_MAX_ACTIVE_INTERFACES,
no_of_if being of type u8 limits the number of interfaces to 255. Introducing USB_MAX_ACTIVE_INTERFACES limit us to the first two interfaces. Is this really needed? Handling all interface would avoid the introduction of artificial limitations which may hit us on the next device.
It's not strictly necessary but assume that the code was only tested with a single interface. Given the general state of u-boot's USB stack I wouldn't be surprised if it would blew up with USB descriptors maxing out the number of interfaces / endpoints. So limiting it to the minimum of what's needed to support the device in front of me looks like the safer option.
Janne