diff options
| author | Ming Lei <tom.leiming@gmail.com> | 2010-09-30 16:32:44 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-10-22 21:22:00 +0400 |
| commit | 689d6eacd1b7c3677bfe6ee367766f21c3c80e26 (patch) | |
| tree | 2524c96c3e6dbd6244292a2a4d0ba769564d5ecf /drivers/usb/host | |
| parent | 00be545e49d83485d49a598d3b7e090088934be8 (diff) | |
| download | linux-689d6eacd1b7c3677bfe6ee367766f21c3c80e26.tar.xz | |
USB: UHCI: add native scatter-gather support(v1)
This patch adds native scatter-gather support to uhci-hcd.
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host')
| -rw-r--r-- | drivers/usb/host/uhci-q.c | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c index d3ade4018487..2090b45eb606 100644 --- a/drivers/usb/host/uhci-q.c +++ b/drivers/usb/host/uhci-q.c @@ -917,10 +917,13 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, unsigned long destination, status; int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize); int len = urb->transfer_buffer_length; - dma_addr_t data = urb->transfer_dma; + int this_sg_len; + dma_addr_t data; __le32 *plink; struct urb_priv *urbp = urb->hcpriv; unsigned int toggle; + struct scatterlist *sg; + int i; if (len < 0) return -EINVAL; @@ -937,12 +940,26 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, if (usb_pipein(urb->pipe)) status |= TD_CTRL_SPD; + i = urb->num_sgs; + if (len > 0 && i > 0) { + sg = urb->sg; + data = 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; + data = urb->transfer_dma; + this_sg_len = len; + } /* * Build the DATA TDs */ plink = NULL; td = qh->dummy_td; - do { /* Allow zero length packets */ + for (;;) { /* Allow zero length packets */ int pktsze = maxsze; if (len <= pktsze) { /* The last packet */ @@ -965,10 +982,18 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, plink = &td->link; status |= TD_CTRL_ACTIVE; + toggle ^= 1; data += pktsze; + this_sg_len -= pktsze; len -= maxsze; - toggle ^= 1; - } while (len > 0); + if (this_sg_len <= 0) { + if (--i <= 0 || len <= 0) + break; + sg = sg_next(sg); + data = sg_dma_address(sg); + this_sg_len = min_t(int, sg_dma_len(sg), len); + } + } /* * URB_ZERO_PACKET means adding a 0-length packet, if direction |