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Commit 30a65b45 authored by Mathias Nyman's avatar Mathias Nyman Committed by Greg Kroah-Hartman
Browse files

xhci: cleanup and refactor process_bulk_intr_td() 



mostly refactoring, but does also change error message if
we get a bad length in the event trb.

Adds a helper function to sum trb lengths of partial TDs

Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0b6c324c

drivers/usb/host/xhci-ring.c

+46 −62
Original line number Diff line number Diff line
@@ -1919,6 +1919,21 @@ static int finish_td(struct xhci_hcd *xhci, struct xhci_td *td, 
	return ret;

}



/* sum trb lengths from ring dequeue up to stop_trb, _excluding_ stop_trb */

static int sum_trb_lengths(struct xhci_hcd *xhci, struct xhci_ring *ring,

			   union xhci_trb *stop_trb)

{

	u32 sum;

	union xhci_trb *trb = ring->dequeue;

	struct xhci_segment *seg = ring->deq_seg;



	for (sum = 0; trb != stop_trb; next_trb(xhci, ring, &seg, &trb)) {

		if (!trb_is_noop(trb) && !trb_is_link(trb))

			sum += TRB_LEN(le32_to_cpu(trb->generic.field[2]));

	}

	return sum;

}



/*

 * Process control tds, update urb status and actual_length.

 */
@@ -2140,88 +2155,57 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td, 
	struct xhci_virt_ep *ep, int *status)

{

	struct xhci_ring *ep_ring;

	union xhci_trb *cur_trb;

	struct xhci_segment *cur_seg;

	u32 trb_comp_code;

	u32 remaining, requested, event_trb_len;



	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));

	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));

	remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));

	event_trb_len =	TRB_LEN(le32_to_cpu(event_trb->generic.field[2]));

	requested = td->urb->transfer_buffer_length;



	switch (trb_comp_code) {

	case COMP_SUCCESS:

		/* Double check that the HW transferred everything. */

		if (event_trb != td->last_trb ||

		    EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {

		/* handle success with untransferred data as short packet */

		if (event_trb != td->last_trb || remaining) {

			xhci_warn(xhci, "WARN Successful completion on short TX\n");

			if ((xhci->quirks & XHCI_TRUST_TX_LENGTH))

				trb_comp_code = COMP_SHORT_TX;

			xhci_dbg(xhci, "ep %#x - asked for %d bytes, %d bytes untransferred\n",

				 td->urb->ep->desc.bEndpointAddress,

				 requested, remaining);

		}

		*status = 0;

		break;

	case COMP_STOP_SHORT:

	case COMP_SHORT_TX:

		xhci_dbg(xhci, "ep %#x - asked for %d bytes, %d bytes untransferred\n",

			 td->urb->ep->desc.bEndpointAddress,

			 requested, remaining);

		*status = 0;

		break;

	case COMP_STOP_SHORT:

		td->urb->actual_length = remaining;

		goto finish_td;

	case COMP_STOP_INVAL:

		/* stopped on ep trb with invalid length, exclude it */

		event_trb_len	= 0;

		remaining	= 0;

		break;

	default:

		/* Others already handled above */

		/* do nothing */

		break;

	}

	if (trb_comp_code == COMP_SHORT_TX)

		xhci_dbg(xhci, "ep %#x - asked for %d bytes, "

				"%d bytes untransferred\n",

				td->urb->ep->desc.bEndpointAddress,

				td->urb->transfer_buffer_length,

				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));

	/* Stopped - short packet completion */

	if (trb_comp_code == COMP_STOP_SHORT) {

		td->urb->actual_length =

			EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));



		if (td->urb->transfer_buffer_length <

				td->urb->actual_length) {

			xhci_warn(xhci, "HC gave bad length of %d bytes txed\n",

				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));

			td->urb->actual_length = 0;

			 /* status will be set by usb core for canceled urbs */

		}

	/* Fast path - was this the last TRB in the TD for this URB? */

	} else if (event_trb == td->last_trb) {

		if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {

	if (event_trb == td->last_trb)

		td->urb->actual_length = requested - remaining;

	else

		td->urb->actual_length =

				td->urb->transfer_buffer_length -

				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));

			if (td->urb->transfer_buffer_length <

					td->urb->actual_length) {

				xhci_warn(xhci, "HC gave bad length of %d bytes left\n",

					  EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));

				td->urb->actual_length = 0;

				*status = 0;

			}

			/* Don't overwrite a previously set error code */

			if (*status == -EINPROGRESS)

				*status = 0;

		}

	} else {

		/* Slow path - walk the list, starting from the dequeue

		 * pointer, to get the actual length transferred.

		 */

			sum_trb_lengths(xhci, ep_ring, event_trb) +

			event_trb_len - remaining;

finish_td:

	if (remaining > requested) {

		xhci_warn(xhci, "bad transfer trb length %d in event trb\n",

			  remaining);

		td->urb->actual_length = 0;

		for (cur_trb = ep_ring->dequeue, cur_seg = ep_ring->deq_seg;

				cur_trb != event_trb;

				next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {

			if (!trb_is_noop(cur_trb) && !trb_is_link(cur_trb))

				td->urb->actual_length +=

					TRB_LEN(le32_to_cpu(cur_trb->generic.field[2]));

	}

		/* If the ring didn't stop on a Link or No-op TRB, add

		 * in the actual bytes transferred from the Normal TRB

		 */

		if (trb_comp_code != COMP_STOP_INVAL)

			td->urb->actual_length +=

				TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -

				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));

	}



	return finish_td(xhci, td, event_trb, event, ep, status, false);

}