Change in coreboot[master]: libpayload: Use interrupt transfers for USB hubs

[Julius Werner (Code Review)]

Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/18499 )

Change subject: libpayload: Use interrupt transfers for USB hubs
......................................................................

Patch Set 3: Code-Review+2

(2 comments)

https://review.coreboot.org/c/coreboot/+/18499/3/payloads/libpayload/drivers... 
File payloads/libpayload/drivers/usb/usbhub.c:

https://review.coreboot.org/c/coreboot/+/18499/3/payloads/libpayload/drivers... 
PS3, Line 308: div_round_up(desc.bNbrPorts + 1, 8)
BTW, Linux says here (hub.c#hub_configure())

/* set up the interrupt endpoint                                         
         * We use the EP's maxpacket size instead of (PORTS+1+7)/8               
         * bytes as USB2.0[11.12.3] says because some hubs are known             
         * to send more data (and thus cause overflow).

Not sure if it matters.

https://review.coreboot.org/c/coreboot/+/18499/3/payloads/libpayload/drivers... 
PS3, Line 310: 		return;
Doesn't this need a usb_detach_device()? (I guess technically that was already wrong for generic_hub_init() in the old code.)