Some devices use a clear endpoint halt request as a soft reset, even if
the endpoint is not halted. This will clear the toggle and sequence on the
device side.
xHCI however refuses to reset a non-halted endpoint, so instead
we need to issue a configure endpoint command on xHCI to clear its host
side toggle and sequence, and get it in sync with the device side.
This is a respin of a old patch that was reverted as it had a stale
endpoint context dequeue value which caused regression.
commit 27082e2654dc ("xhci: Clear the host side toggle manually when
endpoint is 'soft reset'")
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 5 ++-
drivers/usb/host/xhci.c | 105 ++++++++++++++++++++++++++++++++++++-------
drivers/usb/host/xhci.h | 2 +
3 files changed, 95 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 86476c6..91a1a82 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1829,9 +1829,10 @@ static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
xhci_queue_reset_ep(xhci, command, slot_id, ep_index, reset_type);
- if (reset_type == EP_HARD_RESET)
+ if (reset_type == EP_HARD_RESET) {
+ ep->ep_state |= EP_HARD_CLEAR_TOGGLE;
xhci_cleanup_stalled_ring(xhci, ep_index, stream_id, td);
-
+ }
xhci_ring_cmd_db(xhci);
}
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f9d8a32..05b22b8 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1356,6 +1356,11 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag
ret = -EINVAL;
goto free_priv;
}
+ if (*ep_state & EP_SOFT_CLEAR_TOGGLE) {
+ xhci_warn(xhci, "Can't enqueue URB while manually clearing toggle\n");
+ ret = -EINVAL;
+ goto free_priv;
+ }
switch (usb_endpoint_type(&urb->ep->desc)) {
@@ -2869,33 +2874,103 @@ void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci, unsigned int ep_index,
}
}
-/* Called when clearing halted device. The core should have sent the control
- * message to clear the device halt condition. The host side of the halt should
- * already be cleared with a reset endpoint command issued when the STALL tx
- * event was received.
+/*
+ * Called after usb core issues a clear halt control message.
+ * The host side of the halt should already be cleared by a reset endpoint
+ * command issued when the STALL event was received.
*
- * Context: in_interrupt
+ * The reset endpoint command may only be issued to endpoints in the halted
+ * state. For software that wishes to reset the data toggle or sequence number
+ * of an endpoint that isn't in the halted state this function will issue a
+ * configure endpoint command with the Drop and Add bits set for the target
+ * endpoint. Refer to the additional note in xhci spcification section 4.6.8.
*/
static void xhci_endpoint_reset(struct usb_hcd *hcd,
- struct usb_host_endpoint *ep)
+ struct usb_host_endpoint *host_ep)
{
struct xhci_hcd *xhci;
+ struct usb_device *udev;
+ struct xhci_virt_device *vdev;
+ struct xhci_virt_ep *ep;
+ struct xhci_input_control_ctx *ctrl_ctx;
+ struct xhci_command *stop_cmd, *cfg_cmd;
+ unsigned int ep_index;
+ unsigned long flags;
+ u32 ep_flag;
xhci = hcd_to_xhci(hcd);
+ if (!host_ep->hcpriv)
+ return;
+ udev = (struct usb_device *) host_ep->hcpriv;
+ vdev = xhci->devs[udev->slot_id];
+ ep_index = xhci_get_endpoint_index(&host_ep->desc);
+ ep = &vdev->eps[ep_index];
+
+ /* Bail out if toggle is already being cleared by a endpoint reset */
+ if (ep->ep_state & EP_HARD_CLEAR_TOGGLE) {
+ ep->ep_state &= ~EP_HARD_CLEAR_TOGGLE;
+ return;
+ }
+ /* Only interrupt and bulk ep's use data toggle, USB2 spec 5.5.4-> */
+ if (usb_endpoint_xfer_control(&host_ep->desc) ||
+ usb_endpoint_xfer_isoc(&host_ep->desc))
+ return;
+
+ ep_flag = xhci_get_endpoint_flag(&host_ep->desc);
+
+ if (ep_flag == SLOT_FLAG || ep_flag == EP0_FLAG)
+ return;
+
+ stop_cmd = xhci_alloc_command(xhci, true, GFP_NOWAIT);
+ if (!stop_cmd)
+ return;
+
+ cfg_cmd = xhci_alloc_command_with_ctx(xhci, true, GFP_NOWAIT);
+ if (!cfg_cmd)
+ goto cleanup;
+
+ spin_lock_irqsave(&xhci->lock, flags);
+
+ /* block queuing new trbs and ringing ep doorbell */
+ ep->ep_state |= EP_SOFT_CLEAR_TOGGLE;
/*
- * We might need to implement the config ep cmd in xhci 4.8.1 note:
- * The Reset Endpoint Command may only be issued to endpoints in the
- * Halted state. If software wishes reset the Data Toggle or Sequence
- * Number of an endpoint that isn't in the Halted state, then software
- * may issue a Configure Endpoint Command with the Drop and Add bits set
- * for the target endpoint. that is in the Stopped state.
+ * Make sure endpoint ring is empty before resetting the toggle/seq.
+ * Driver is required to synchronously cancel all transfer request.
+ * Stop the endpoint to force xHC to update the output context
*/
- /* For now just print debug to follow the situation */
- xhci_dbg(xhci, "Endpoint 0x%x ep reset callback called\n",
- ep->desc.bEndpointAddress);
+ if (!list_empty(&ep->ring->td_list)) {
+ dev_err(&udev->dev, "EP not empty, refuse reset\n");
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ goto cleanup;
+ }
+ xhci_queue_stop_endpoint(xhci, stop_cmd, udev->slot_id, ep_index, 0);
+ xhci_ring_cmd_db(xhci);
+ spin_unlock_irqrestore(&xhci->lock, flags);
+
+ wait_for_completion(stop_cmd->completion);
+
+ spin_lock_irqsave(&xhci->lock, flags);
+
+ /* config ep command clears toggle if add and drop ep flags are set */
+ ctrl_ctx = xhci_get_input_control_ctx(cfg_cmd->in_ctx);
+ xhci_setup_input_ctx_for_config_ep(xhci, cfg_cmd->in_ctx, vdev->out_ctx,
+ ctrl_ctx, ep_flag, ep_flag);
+ xhci_endpoint_copy(xhci, cfg_cmd->in_ctx, vdev->out_ctx, ep_index);
+
+ xhci_queue_configure_endpoint(xhci, cfg_cmd, cfg_cmd->in_ctx->dma,
+ udev->slot_id, false);
+ xhci_ring_cmd_db(xhci);
+ spin_unlock_irqrestore(&xhci->lock, flags);
+
+ wait_for_completion(cfg_cmd->completion);
+
+ ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
+ xhci_free_command(xhci, cfg_cmd);
+cleanup:
+ xhci_free_command(xhci, stop_cmd);
}
static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index e4d7d3d..9f236da 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -921,6 +921,8 @@ struct xhci_virt_ep {
#define EP_HAS_STREAMS (1 << 4)
/* Transitioning the endpoint to not using streams, don't enqueue URBs */
#define EP_GETTING_NO_STREAMS (1 << 5)
+#define EP_HARD_CLEAR_TOGGLE (1 << 6)
+#define EP_SOFT_CLEAR_TOGGLE (1 << 7)
/* ---- Related to URB cancellation ---- */
struct list_head cancelled_td_list;
/* Watchdog timer for stop endpoint command to cancel URBs */
--
2.7.4
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