[PATCH v2 4/8] usb: xhci: Recover from halted bulk endpoints

[Hector Martin]

There is currently no codepath to recover from this case. In principle
we could require that the upper layer do this explicitly, but let's just
do it in xHCI when the next bulk transfer is started, since that
reasonably implies whatever caused the problem has been dealt with.

Signed-off-by: Hector Martin <marcan at marcan.st>
---
 drivers/usb/host/xhci-ring.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index e02a6e300c4f..db8b8f200250 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -671,6 +671,14 @@ int xhci_bulk_tx(struct usb_device *udev, unsigned long pipe,
 
 	ep_ctx = xhci_get_ep_ctx(ctrl, virt_dev->out_ctx, ep_index);
 
+	/*
+	 * If the endpoint was halted due to a prior error, resume it before
+	 * the next transfer. It is the responsibility of the upper layer to
+	 * have dealt with whatever caused the error.
+	 */
+	if ((le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK) == EP_STATE_HALTED)
+		reset_ep(udev, ep_index);
+
 	ring = virt_dev->eps[ep_index].ring;
 	/*
 	 * How much data is (potentially) left before the 64KB boundary?

-- 
2.41.0