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 <bmeng.cn@gmail.com>

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 84982a92d6030efbdab5437a94199b3c4c60ab90..0582a9be40add12c86430bacd617e6ba07f28bef 100644 (file)
--- 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 93737b083cb8a31023ef921aee3a8da399f711c1..4673738d1e8985411c77fe6a8a19a82e421b1308 100644 (file)
--- 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));