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Commit 4758dcd1 authored by Reyad Attiyat's avatar Reyad Attiyat Committed by Greg Kroah-Hartman
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usb: xhci: Add support for URB_ZERO_PACKET to bulk/sg transfers 



This commit checks for the URB_ZERO_PACKET flag and creates an extra
zero-length td if the urb transfer length is a multiple of the endpoint's
max packet length.

Signed-off-by: default avatarReyad Attiyat <reyad.attiyat@gmail.com>
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6c05cb14

drivers/usb/host/xhci-ring.c

+52 −14
Original line number Diff line number Diff line
@@ -3041,9 +3041,11 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
	struct xhci_td *td;

	struct scatterlist *sg;

	int num_sgs;

	int trb_buff_len, this_sg_len, running_total;

	int trb_buff_len, this_sg_len, running_total, ret;

	unsigned int total_packet_count;

	bool zero_length_needed;

	bool first_trb;

	int last_trb_num;

	u64 addr;

	bool more_trbs_coming;
@@ -3059,13 +3061,27 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
	total_packet_count = DIV_ROUND_UP(urb->transfer_buffer_length,

			usb_endpoint_maxp(&urb->ep->desc));



	trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],

	ret = prepare_transfer(xhci, xhci->devs[slot_id],

			ep_index, urb->stream_id,

			num_trbs, urb, 0, mem_flags);

	if (trb_buff_len < 0)

		return trb_buff_len;

	if (ret < 0)

		return ret;



	urb_priv = urb->hcpriv;



	/* Deal with URB_ZERO_PACKET - need one more td/trb */

	zero_length_needed = urb->transfer_flags & URB_ZERO_PACKET &&

		urb_priv->length == 2;

	if (zero_length_needed) {

		num_trbs++;

		xhci_dbg(xhci, "Creating zero length td.\n");

		ret = prepare_transfer(xhci, xhci->devs[slot_id],

				ep_index, urb->stream_id,

				1, urb, 1, mem_flags);

		if (ret < 0)

			return ret;

	}



	td = urb_priv->td[0];



	/*
@@ -3095,6 +3111,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		trb_buff_len = urb->transfer_buffer_length;



	first_trb = true;

	last_trb_num = zero_length_needed ? 2 : 1;

	/* Queue the first TRB, even if it's zero-length */

	do {

		u32 field = 0;
@@ -3112,12 +3129,15 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		/* Chain all the TRBs together; clear the chain bit in the last

		 * TRB to indicate it's the last TRB in the chain.

		 */

		if (num_trbs > 1) {

		if (num_trbs > last_trb_num) {

			field |= TRB_CHAIN;

		} else {

			/* FIXME - add check for ZERO_PACKET flag before this */

		} else if (num_trbs == last_trb_num) {

			td->last_trb = ep_ring->enqueue;

			field |= TRB_IOC;

		} else if (zero_length_needed && num_trbs == 1) {

			trb_buff_len = 0;

			urb_priv->td[1]->last_trb = ep_ring->enqueue;

			field |= TRB_IOC;

		}



		/* Only set interrupt on short packet for IN endpoints */
@@ -3179,7 +3199,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		if (running_total + trb_buff_len > urb->transfer_buffer_length)

			trb_buff_len =

				urb->transfer_buffer_length - running_total;

	} while (running_total < urb->transfer_buffer_length);

	} while (num_trbs > 0);



	check_trb_math(urb, num_trbs, running_total);

	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
@@ -3197,7 +3217,9 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
	int num_trbs;

	struct xhci_generic_trb *start_trb;

	bool first_trb;

	int last_trb_num;

	bool more_trbs_coming;

	bool zero_length_needed;

	int start_cycle;

	u32 field, length_field;
@@ -3228,7 +3250,6 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		num_trbs++;

		running_total += TRB_MAX_BUFF_SIZE;

	}

	/* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */



	ret = prepare_transfer(xhci, xhci->devs[slot_id],

			ep_index, urb->stream_id,
@@ -3237,6 +3258,20 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		return ret;



	urb_priv = urb->hcpriv;



	/* Deal with URB_ZERO_PACKET - need one more td/trb */

	zero_length_needed = urb->transfer_flags & URB_ZERO_PACKET &&

		urb_priv->length == 2;

	if (zero_length_needed) {

		num_trbs++;

		xhci_dbg(xhci, "Creating zero length td.\n");

		ret = prepare_transfer(xhci, xhci->devs[slot_id],

				ep_index, urb->stream_id,

				1, urb, 1, mem_flags);

		if (ret < 0)

			return ret;

	}



	td = urb_priv->td[0];



	/*
@@ -3258,7 +3293,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		trb_buff_len = urb->transfer_buffer_length;



	first_trb = true;



	last_trb_num = zero_length_needed ? 2 : 1;

	/* Queue the first TRB, even if it's zero-length */

	do {

		u32 remainder = 0;
@@ -3275,12 +3310,15 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		/* Chain all the TRBs together; clear the chain bit in the last

		 * TRB to indicate it's the last TRB in the chain.

		 */

		if (num_trbs > 1) {

		if (num_trbs > last_trb_num) {

			field |= TRB_CHAIN;

		} else {

			/* FIXME - add check for ZERO_PACKET flag before this */

		} else if (num_trbs == last_trb_num) {

			td->last_trb = ep_ring->enqueue;

			field |= TRB_IOC;

		} else if (zero_length_needed && num_trbs == 1) {

			trb_buff_len = 0;

			urb_priv->td[1]->last_trb = ep_ring->enqueue;

			field |= TRB_IOC;

		}



		/* Only set interrupt on short packet for IN endpoints */
@@ -3318,7 +3356,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, 
		trb_buff_len = urb->transfer_buffer_length - running_total;

		if (trb_buff_len > TRB_MAX_BUFF_SIZE)

			trb_buff_len = TRB_MAX_BUFF_SIZE;

	} while (running_total < urb->transfer_buffer_length);

	} while (num_trbs > 0);



	check_trb_math(urb, num_trbs, running_total);

	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,

drivers/usb/host/xhci.c

+5 −0
Original line number Diff line number Diff line
@@ -1340,6 +1340,11 @@ int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags) 


	if (usb_endpoint_xfer_isoc(&urb->ep->desc))

		size = urb->number_of_packets;

	else if (usb_endpoint_is_bulk_out(&urb->ep->desc) &&

	    urb->transfer_buffer_length > 0 &&

	    urb->transfer_flags & URB_ZERO_PACKET &&

	    !(urb->transfer_buffer_length % usb_endpoint_maxp(&urb->ep->desc)))

		size = 2;

	else

		size = 1;