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Commit ef513be0 authored by Jim Lin's avatar Jim Lin Committed by Greg Kroah-Hartman
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usb: xhci: Add Clear_TT_Buffer 



USB 2.0 specification chapter 11.17.5 says "as part of endpoint halt
processing for full-/low-speed endpoints connected via a TT, the host
software must use the Clear_TT_Buffer request to the TT to ensure
that the buffer is not in the busy state".

In our case, a full-speed speaker (ConferenceCam) is behind a high-
speed hub (ConferenceCam Connect), sometimes once we get STALL on a
request we may continue to get STALL with the folllowing requests,
like Set_Interface.

Here we invoke usb_hub_clear_tt_buffer() to send Clear_TT_Buffer
request to the hub of the device for the following Set_Interface
requests to the device to get ACK successfully.

Signed-off-by: default avatarJim Lin <jilin@nvidia.com>
Acked-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4998f1ef

drivers/usb/host/xhci-ring.c

+26 −1
Original line number Diff line number Diff line
@@ -399,7 +399,7 @@ void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, 
	 * stream once the endpoint is on the HW schedule.

	 */

	if ((ep_state & EP_STOP_CMD_PENDING) || (ep_state & SET_DEQ_PENDING) ||

	    (ep_state & EP_HALTED))

	    (ep_state & EP_HALTED) || (ep_state & EP_CLEARING_TT))

		return;

	writel(DB_VALUE(ep_index, stream_id), db_addr);

	/* The CPU has better things to do at this point than wait for a
@@ -433,6 +433,13 @@ static void ring_doorbell_for_active_rings(struct xhci_hcd *xhci, 
	}

}



void xhci_ring_doorbell_for_active_rings(struct xhci_hcd *xhci,

		unsigned int slot_id,

		unsigned int ep_index)

{

	ring_doorbell_for_active_rings(xhci, slot_id, ep_index);

}



/* Get the right ring for the given slot_id, ep_index and stream_id.

 * If the endpoint supports streams, boundary check the URB's stream ID.

 * If the endpoint doesn't support streams, return the singular endpoint ring.
@@ -1794,6 +1801,23 @@ struct xhci_segment *trb_in_td(struct xhci_hcd *xhci, 
	return NULL;

}



static void xhci_clear_hub_tt_buffer(struct xhci_hcd *xhci, struct xhci_td *td,

		struct xhci_virt_ep *ep)

{

	/*

	 * As part of low/full-speed endpoint-halt processing

	 * we must clear the TT buffer (USB 2.0 specification 11.17.5).

	 */

	if (td->urb->dev->tt && !usb_pipeint(td->urb->pipe) &&

	    (td->urb->dev->tt->hub != xhci_to_hcd(xhci)->self.root_hub) &&

	    !(ep->ep_state & EP_CLEARING_TT)) {

		ep->ep_state |= EP_CLEARING_TT;

		td->urb->ep->hcpriv = td->urb->dev;

		if (usb_hub_clear_tt_buffer(td->urb))

			ep->ep_state &= ~EP_CLEARING_TT;

	}

}



static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,

		unsigned int slot_id, unsigned int ep_index,

		unsigned int stream_id, struct xhci_td *td,
@@ -1812,6 +1836,7 @@ static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci, 
	if (reset_type == EP_HARD_RESET) {

		ep->ep_state |= EP_HARD_CLEAR_TOGGLE;

		xhci_cleanup_stalled_ring(xhci, ep_index, stream_id, td);

		xhci_clear_hub_tt_buffer(xhci, td, ep);

	}

	xhci_ring_cmd_db(xhci);

}

drivers/usb/host/xhci.c

+21 −0
Original line number Diff line number Diff line
@@ -5163,6 +5163,26 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks) 
}

EXPORT_SYMBOL_GPL(xhci_gen_setup);



static void xhci_clear_tt_buffer_complete(struct usb_hcd *hcd,

		struct usb_host_endpoint *ep)

{

	struct xhci_hcd *xhci;

	struct usb_device *udev;

	unsigned int slot_id;

	unsigned int ep_index;

	unsigned long flags;



	xhci = hcd_to_xhci(hcd);

	udev = (struct usb_device *)ep->hcpriv;

	slot_id = udev->slot_id;

	ep_index = xhci_get_endpoint_index(&ep->desc);



	spin_lock_irqsave(&xhci->lock, flags);

	xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_CLEARING_TT;

	xhci_ring_doorbell_for_active_rings(xhci, slot_id, ep_index);

	spin_unlock_irqrestore(&xhci->lock, flags);

}



static const struct hc_driver xhci_hc_driver = {

	.description =		"xhci-hcd",

	.product_desc =		"xHCI Host Controller",
@@ -5224,6 +5244,7 @@ static const struct hc_driver xhci_hc_driver = { 
	.enable_usb3_lpm_timeout =	xhci_enable_usb3_lpm_timeout,

	.disable_usb3_lpm_timeout =	xhci_disable_usb3_lpm_timeout,

	.find_raw_port_number =	xhci_find_raw_port_number,

	.clear_tt_buffer_complete = xhci_clear_tt_buffer_complete,

};



void xhci_init_driver(struct hc_driver *drv,

drivers/usb/host/xhci.h

+5 −0
Original line number Diff line number Diff line
@@ -936,6 +936,8 @@ struct xhci_virt_ep { 
#define EP_GETTING_NO_STREAMS	(1 << 5)

#define EP_HARD_CLEAR_TOGGLE	(1 << 6)

#define EP_SOFT_CLEAR_TOGGLE	(1 << 7)

/* usb_hub_clear_tt_buffer is in progress */

#define EP_CLEARING_TT		(1 << 8)

	/* ----  Related to URB cancellation ---- */

	struct list_head	cancelled_td_list;

	/* Watchdog timer for stop endpoint command to cancel URBs */
@@ -2102,6 +2104,9 @@ void xhci_handle_command_timeout(struct work_struct *work); 


void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, unsigned int slot_id,

		unsigned int ep_index, unsigned int stream_id);

void xhci_ring_doorbell_for_active_rings(struct xhci_hcd *xhci,

		unsigned int slot_id,

		unsigned int ep_index);

void xhci_cleanup_command_queue(struct xhci_hcd *xhci);

void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring);

unsigned int count_trbs(u64 addr, u64 len);