diff options
author | Thomas Pugliese <thomas.pugliese@gmail.com> | 2014-03-07 15:37:34 -0600 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-08 22:30:28 -0800 |
commit | 04a378f36d9dc9e242ff206fcad23ba258dba818 (patch) | |
tree | b28e1ad06cffbdb07190eb83a6259485bbc99a82 /drivers/usb/wusbcore/wa-xfer.c | |
parent | 7338a0659365ec0fbdc6f79de8b9fba2280fd155 (diff) | |
download | op-kernel-dev-04a378f36d9dc9e242ff206fcad23ba258dba818.zip op-kernel-dev-04a378f36d9dc9e242ff206fcad23ba258dba818.tar.gz |
usb: wusbcore: combine iso transfer result frame reads when possible
When reading the transfer result data for an isochronous in request, if
the current frame actual_length is contiguous with the next frame and
actual_length is a multiple of the DTI endpoint max packet size, combine
the current frame with the next frame in a single URB. This reduces the
number of URBs that must be submitted in that case which increases
performance and reduces CPU interrupt overhead.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/wusbcore/wa-xfer.c')
-rw-r--r-- | drivers/usb/wusbcore/wa-xfer.c | 106 |
1 files changed, 76 insertions, 30 deletions
diff --git a/drivers/usb/wusbcore/wa-xfer.c b/drivers/usb/wusbcore/wa-xfer.c index 52c7259..f930bbb 100644 --- a/drivers/usb/wusbcore/wa-xfer.c +++ b/drivers/usb/wusbcore/wa-xfer.c @@ -2160,22 +2160,59 @@ static void wa_complete_remaining_xfer_segs(struct wa_xfer *xfer, } /* Populate the wa->buf_in_urb based on the current isoc transfer state. */ -static void __wa_populate_buf_in_urb_isoc(struct wahc *wa, struct wa_xfer *xfer, - struct wa_seg *seg, int curr_iso_frame) +static int __wa_populate_buf_in_urb_isoc(struct wahc *wa, struct wa_xfer *xfer, + struct wa_seg *seg) { + int urb_start_frame = seg->isoc_frame_index + seg->isoc_frame_offset; + int seg_index, total_len = 0, urb_frame_index = urb_start_frame; + struct usb_iso_packet_descriptor *iso_frame_desc = + xfer->urb->iso_frame_desc; + const int dti_packet_size = usb_endpoint_maxp(wa->dti_epd); + int next_frame_contiguous; + struct usb_iso_packet_descriptor *iso_frame; + BUG_ON(wa->buf_in_urb->status == -EINPROGRESS); + /* + * If the current frame actual_length is contiguous with the next frame + * and actual_length is a multiple of the DTI endpoint max packet size, + * combine the current frame with the next frame in a single URB. This + * reduces the number of URBs that must be submitted in that case. + */ + seg_index = seg->isoc_frame_index; + do { + next_frame_contiguous = 0; + + iso_frame = &iso_frame_desc[urb_frame_index]; + total_len += iso_frame->actual_length; + ++urb_frame_index; + ++seg_index; + + if (seg_index < seg->isoc_frame_count) { + struct usb_iso_packet_descriptor *next_iso_frame; + + next_iso_frame = &iso_frame_desc[urb_frame_index]; + + if ((iso_frame->offset + iso_frame->actual_length) == + next_iso_frame->offset) + next_frame_contiguous = 1; + } + } while (next_frame_contiguous + && ((iso_frame->actual_length % dti_packet_size) == 0)); + /* this should always be 0 before a resubmit. */ wa->buf_in_urb->num_mapped_sgs = 0; wa->buf_in_urb->transfer_dma = xfer->urb->transfer_dma + - xfer->urb->iso_frame_desc[curr_iso_frame].offset; - wa->buf_in_urb->transfer_buffer_length = - xfer->urb->iso_frame_desc[curr_iso_frame].actual_length; + iso_frame_desc[urb_start_frame].offset; + wa->buf_in_urb->transfer_buffer_length = total_len; wa->buf_in_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; wa->buf_in_urb->transfer_buffer = NULL; wa->buf_in_urb->sg = NULL; wa->buf_in_urb->num_sgs = 0; wa->buf_in_urb->context = seg; + + /* return the number of frames included in this URB. */ + return seg_index - seg->isoc_frame_index; } /* Populate the wa->buf_in_urb based on the current transfer state. */ @@ -2458,19 +2495,20 @@ static int wa_process_iso_packet_status(struct wahc *wa, struct urb *urb) } if (xfer->is_inbound && data_frame_count) { - int result; + int result, urb_frame_count; seg->isoc_frame_index = first_frame_index; /* submit a read URB for the first frame with data. */ - __wa_populate_buf_in_urb_isoc(wa, xfer, seg, - seg->isoc_frame_index + seg->isoc_frame_offset); + urb_frame_count = __wa_populate_buf_in_urb_isoc(wa, xfer, seg); + /* advance index to start of next read URB. */ + seg->isoc_frame_index += urb_frame_count; result = usb_submit_urb(wa->buf_in_urb, GFP_ATOMIC); if (result < 0) { dev_err(dev, "DTI Error: Could not submit buf in URB (%d)", result); wa_reset_all(wa); - } else if (data_frame_count > 1) + } else if (data_frame_count > urb_frame_count) /* If we need to read multiple frames, set DTI busy. */ dti_busy = 1; } else { @@ -2511,8 +2549,9 @@ static void wa_buf_in_cb(struct urb *urb) struct wahc *wa; struct device *dev; struct wa_rpipe *rpipe; - unsigned rpipe_ready = 0, seg_index, isoc_data_frame_count = 0; + unsigned rpipe_ready = 0, isoc_data_frame_count = 0; unsigned long flags; + int resubmit_dti = 0; u8 done = 0; /* free the sg if it was used. */ @@ -2524,17 +2563,16 @@ static void wa_buf_in_cb(struct urb *urb) dev = &wa->usb_iface->dev; if (usb_pipeisoc(xfer->urb->pipe)) { + struct usb_iso_packet_descriptor *iso_frame_desc = + xfer->urb->iso_frame_desc; + int seg_index; + /* - * Find the next isoc frame with data. Bail out after - * isoc_data_frame_count > 1 since there is no need to walk - * the entire frame array. We just need to know if - * isoc_data_frame_count is 0, 1, or >1. + * Find the next isoc frame with data and count how many + * frames with data remain. */ - seg_index = seg->isoc_frame_index + 1; - while ((seg_index < seg->isoc_frame_count) - && (isoc_data_frame_count <= 1)) { - struct usb_iso_packet_descriptor *iso_frame_desc = - xfer->urb->iso_frame_desc; + seg_index = seg->isoc_frame_index; + while (seg_index < seg->isoc_frame_count) { const int urb_frame_index = seg->isoc_frame_offset + seg_index; @@ -2555,16 +2593,28 @@ static void wa_buf_in_cb(struct urb *urb) seg->result += urb->actual_length; if (isoc_data_frame_count > 0) { - int result; - /* submit a read URB for the first frame with data. */ - __wa_populate_buf_in_urb_isoc(wa, xfer, seg, - seg->isoc_frame_index + seg->isoc_frame_offset); + int result, urb_frame_count; + + /* submit a read URB for the next frame with data. */ + urb_frame_count = __wa_populate_buf_in_urb_isoc(wa, + xfer, seg); + /* advance index to start of next read URB. */ + seg->isoc_frame_index += urb_frame_count; result = usb_submit_urb(wa->buf_in_urb, GFP_ATOMIC); if (result < 0) { dev_err(dev, "DTI Error: Could not submit buf in URB (%d)", result); wa_reset_all(wa); } + /* + * If we are in this callback and + * isoc_data_frame_count > 0, it means that the dti_urb + * submission was delayed in wa_dti_cb. Once + * we submit the last buf_in_urb, we can submit the + * delayed dti_urb. + */ + resubmit_dti = (isoc_data_frame_count == + urb_frame_count); } else { rpipe = xfer->ep->hcpriv; dev_dbg(dev, @@ -2585,6 +2635,7 @@ static void wa_buf_in_cb(struct urb *urb) case -ENOENT: /* as it was done by the who unlinked us */ break; default: /* Other errors ... */ + resubmit_dti = 1; spin_lock_irqsave(&xfer->lock, flags); rpipe = xfer->ep->hcpriv; if (printk_ratelimit()) @@ -2607,13 +2658,8 @@ static void wa_buf_in_cb(struct urb *urb) if (rpipe_ready) wa_xfer_delayed_run(rpipe); } - /* - * If we are in this callback and isoc_data_frame_count > 0, it means - * that the dti_urb submission was delayed in wa_dti_cb. Once - * isoc_data_frame_count gets to 1, we can submit the deferred URB - * since the last buf_in_urb was just submitted. - */ - if (isoc_data_frame_count == 1) { + + if (resubmit_dti) { int result = usb_submit_urb(wa->dti_urb, GFP_ATOMIC); if (result < 0) { dev_err(dev, "DTI Error: Could not submit DTI URB (%d)\n", |