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Commit 40f8db8f authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: EHCI: add native scatter-gather support 



This patch (as1300) adds native scatter-gather support to ehci-hcd.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3a2b808e

drivers/usb/host/ehci-hcd.c

+2 −0
Original line number Diff line number Diff line
@@ -605,6 +605,8 @@ static int ehci_init(struct usb_hcd *hcd) 
	}

	ehci->command = temp;



	/* Accept arbitrarily long scatter-gather lists */

	hcd->self.sg_tablesize = ~0;

	return 0;

}

drivers/usb/host/ehci-q.c

+27 −5
Original line number Diff line number Diff line
@@ -616,9 +616,11 @@ qh_urb_transaction ( 
) {

	struct ehci_qtd		*qtd, *qtd_prev;

	dma_addr_t		buf;

	int			len, maxpacket;

	int			len, this_sg_len, maxpacket;

	int			is_input;

	u32			token;

	int			i;

	struct scatterlist	*sg;



	/*

	 * URBs map to sequences of QTDs:  one logical transaction
@@ -659,7 +661,20 @@ qh_urb_transaction ( 
	/*

	 * data transfer stage:  buffer setup

	 */

	i = urb->num_sgs;

	if (len > 0 && i > 0) {

		sg = urb->sg->sg;

		buf = sg_dma_address(sg);



		/* urb->transfer_buffer_length may be smaller than the

		 * size of the scatterlist (or vice versa)

		 */

		this_sg_len = min_t(int, sg_dma_len(sg), len);

	} else {

		sg = NULL;

		buf = urb->transfer_dma;

		this_sg_len = len;

	}



	if (is_input)

		token |= (1 /* "in" */ << 8);
@@ -675,7 +690,9 @@ qh_urb_transaction ( 
	for (;;) {

		int this_qtd_len;



		this_qtd_len = qtd_fill(ehci, qtd, buf, len, token, maxpacket);

		this_qtd_len = qtd_fill(ehci, qtd, buf, this_sg_len, token,

				maxpacket);

		this_sg_len -= this_qtd_len;

		len -= this_qtd_len;

		buf += this_qtd_len;
@@ -691,8 +708,13 @@ qh_urb_transaction ( 
		if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)

			token ^= QTD_TOGGLE;



		if (likely (len <= 0))

		if (likely(this_sg_len <= 0)) {

			if (--i <= 0 || len <= 0)

				break;

			sg = sg_next(sg);

			buf = sg_dma_address(sg);

			this_sg_len = min_t(int, sg_dma_len(sg), len);

		}



		qtd_prev = qtd;

		qtd = ehci_qtd_alloc (ehci, flags);