e819f05927
The BCM2711 has two USB 2.0 IPs: A Broadcom XHCI USB 2.0 controller and a Synopsys DWC2 USB 2.0 Host/Device controller. When USB boot is used the former is active. Make sure the driver has the correct device tree compatible.
88 lines
3.2 KiB
Diff
88 lines
3.2 KiB
Diff
From 3d471d3be58ccd899d29bf57ad669e7a51d0b47d Mon Sep 17 00:00:00 2001
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Message-Id: <3d471d3be58ccd899d29bf57ad669e7a51d0b47d.1633601057.git.stefan@agner.ch>
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In-Reply-To: <d7ec084799b394cc02395829dc97019c8834e944.1633601057.git.stefan@agner.ch>
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References: <d7ec084799b394cc02395829dc97019c8834e944.1633601057.git.stefan@agner.ch>
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From: Stefan Agner <stefan@agner.ch>
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Date: Mon, 27 Sep 2021 12:28:04 +0200
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Subject: [PATCH 02/10] usb: xhci: reset endpoint on USB stall
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There are devices which cause a USB stall when trying to read strings.
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Specifically Arduino Mega R3 stalls when trying to read the product
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string.
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The stall currently remains unhandled, and subsequent retries submit new
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transfers on a stopped endpoint which ultimately cause a crash in
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abort_td():
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WARN halted endpoint, queueing URB anyway.
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XHCI control transfer timed out, aborting...
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Unexpected XHCI event TRB, skipping... (3affe040 00000000 13000000 02008401)
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BUG at drivers/usb/host/xhci-ring.c:505/abort_td()!
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BUG!
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resetting ...
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Linux seems to be able to recover from the stall by issuing a
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TRB_RESET_EP command.
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Introduce reset_ep() which issues a TRB_RESET_EP followed by setting the
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transfer ring dequeue pointer via TRB_SET_DEQ. This allows to properly
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recover from a USB stall error and continue communicating with the USB
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device.
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Signed-off-by: Stefan Agner <stefan@agner.ch>
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---
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drivers/usb/host/xhci-ring.c | 31 +++++++++++++++++++++++++++++++
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1 file changed, 31 insertions(+)
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diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
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index 35bd5cd29e..430823cb9d 100644
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--- a/drivers/usb/host/xhci-ring.c
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+++ b/drivers/usb/host/xhci-ring.c
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@@ -481,6 +481,33 @@ union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected)
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BUG();
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}
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+/*
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+ * Issue reset endpoint command for an endpoint. This is required to recover
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+ * a halted endpoint (e.g. due to a stall error).
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+ */
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+static void reset_ep(struct usb_device *udev, int ep_index)
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+{
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+ struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
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+ struct xhci_ring *ring = ctrl->devs[udev->slot_id]->eps[ep_index].ring;
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+ union xhci_trb *event;
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+ u32 field;
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+
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+ printf("Resetting EP...\n");
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+ xhci_queue_command(ctrl, NULL, udev->slot_id, ep_index, TRB_RESET_EP);
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+ event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
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+ field = le32_to_cpu(event->trans_event.flags);
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+ BUG_ON(TRB_TO_SLOT_ID(field) != udev->slot_id);
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+ xhci_acknowledge_event(ctrl);
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+
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+ xhci_queue_command(ctrl, (void *)((uintptr_t)ring->enqueue |
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+ ring->cycle_state), udev->slot_id, ep_index, TRB_SET_DEQ);
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+ event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
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+ BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
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+ != udev->slot_id || GET_COMP_CODE(le32_to_cpu(
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+ event->event_cmd.status)) != COMP_SUCCESS);
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+ xhci_acknowledge_event(ctrl);
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+}
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+
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/*
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* Stops transfer processing for an endpoint and throws away all unprocessed
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* TRBs by setting the xHC's dequeue pointer to our enqueue pointer. The next
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@@ -928,6 +955,10 @@ int xhci_ctrl_tx(struct usb_device *udev, unsigned long pipe,
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record_transfer_result(udev, event, length);
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xhci_acknowledge_event(ctrl);
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+ if (udev->status == USB_ST_STALLED) {
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+ reset_ep(udev, ep_index);
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+ return -EPIPE;
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+ }
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/* Invalidate buffer to make it available to usb-core */
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if (length > 0)
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--
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2.33.0
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