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.pugli...@gmail.com>
---
drivers/usb/wusbcore/wa-xfer.c | 104 +++++++++++++++++++++++++++++------------
1 file changed, 75 insertions(+), 29 deletions(-)
diff --git a/drivers/usb/wusbcore/wa-xfer.c b/drivers/usb/wusbcore/wa-xfer.c
index 6046fee..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;
+ int result, urb_frame_count;
+
/* submit a read URB for the next 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);
}
+ /*
+ * 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",
--
1.8.3.2
--
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