On Fri, Apr 29, 2022 at 01:23:50PM +0300, Mathias Nyman wrote: > On 29.4.2022 13.02, Greg KH wrote: > > On Fri, Apr 29, 2022 at 12:49:59PM +0300, Mathias Nyman wrote: > >> On 28.4.2022 22.04, Mayank Rana wrote: > >>> ring_doorbell_for_active_rings() API is being called from > >>> multiple context. This specific API tries to get virt_dev > >>> based endpoint using passed slot_id and ep_index. Some caller > >>> API is having check against slot_id and ep_index using > >>> xhci_get_virt_ep() API whereas xhci_handle_cmd_config_ep() API > >>> only check ep_index against -1 value but not upper bound i.e. > >>> EP_CTX_PER_DEV. Hence use xhci_get_virt_ep() API to get virt_dev > >>> based endpoint which checks both slot_id and ep_index to get > >>> valid endpoint. > >> > >> ep_index upper bound is known to be in range as EP_CTX_PER_DEV is 31, > >> and ep_index = fls(u32 value) - 1 - 1; > >> > >> We can change to use xhci_get_virt_ep(), but this would be more useful > >> earlier in xhci_handle_cmd_config_ep() where we touch the ep before > >> calling ring_doorbell_for_active_rings() > >> > >> Also note that this codepath is only used for some prototype > >> xHC controller that probably never made it to the market about 10 years ago. > > > > Can we just delete the codepath entirely then? > > Probably. > Commit ac9d8fe7c6a8 USB: xhci: Add quirk for Fresco Logic xHCI hardware. > that added this states: > > "This patch is for prototype hardware that will be given to other companies > for evaluation purposes only, and should not reach consumer hands. Fresco > Logic's next chip rev should have this bug fixed." > > Should we print some warning instead if this controller is used? > just in case. Would be a good idea, see if that hardware did actually get out into the wild. thanks, greg k-h
