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. Thanks Mathias
