From fae35857e1c38776854442f59d6b56c17e93fc39 Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Mon, 18 Sep 2017 06:40:50 -0700 Subject: [PATCH] usb: xhci: Set 'Average TRB Length' to 8 for control endpoints Update the codes to conform with xHCI spec chapter 6.2.3. Signed-off-by: Bin Meng --- drivers/usb/host/xhci-mem.c | 6 ++++++ drivers/usb/host/xhci.c | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 84982a92d6..0582a9be40 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -850,6 +850,12 @@ void xhci_setup_addressable_virt_dev(struct xhci_ctrl *ctrl, trb_64 = (uintptr_t)virt_dev->eps[0].ring->first_seg->trbs; ep0_ctx->deq = cpu_to_le64(trb_64 | virt_dev->eps[0].ring->cycle_state); + /* + * xHCI spec 6.2.3: + * software shall set 'Average TRB Length' to 8 for control endpoints. + */ + ep0_ctx->tx_info = cpu_to_le32(EP_AVG_TRB_LENGTH(8)); + /* Steps 7 and 8 were done in xhci_alloc_virt_device() */ xhci_flush_cache((uintptr_t)ep0_ctx, sizeof(struct xhci_ep_ctx)); diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 93737b083c..4673738d1e 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -601,6 +601,12 @@ static int xhci_set_configuration(struct usb_device *udev) ep_ctx[ep_index]->deq = cpu_to_le64(trb_64 | virt_dev->eps[ep_index].ring->cycle_state); + /* + * xHCI spec 6.2.3: + * 'Average TRB Length' should be 8 for control endpoints. + */ + if (usb_endpoint_xfer_control(endpt_desc)) + avg_trb_len = 8; ep_ctx[ep_index]->tx_info = cpu_to_le32(EP_MAX_ESIT_PAYLOAD_LO(max_esit_payload) | EP_AVG_TRB_LENGTH(avg_trb_len)); -- 2.30.2