]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - drivers/usb/wusbcore/wa-xfer.c
usb: wusbcore: combine multiple isoc frames in a single transfer request.
[karo-tx-linux.git] / drivers / usb / wusbcore / wa-xfer.c
index f1e9a386beca6a4a92da3242796ec78afccd4e5a..9325d27453c4ee93e1217cc9bfb7ae2e4de11f9a 100644 (file)
@@ -121,6 +121,9 @@ struct wa_seg {
        struct list_head list_node;     /* for rpipe->req_list */
        struct wa_xfer *xfer;           /* out xfer */
        u8 index;                       /* which segment we are */
+       int isoc_frame_count;   /* number of isoc frames in this segment. */
+       int isoc_frame_offset;  /* starting frame offset in the xfer URB. */
+       int isoc_size;  /* size of all isoc frames sent by this seg. */
        enum wa_seg_status status;
        ssize_t result;                 /* bytes xfered or error */
        struct wa_xfer_hdr xfer_hdr;
@@ -154,12 +157,17 @@ struct wa_xfer {
        unsigned is_dma:1;
        size_t seg_size;
        int result;
+       /* Isoc frame that the current transfer buffer corresponds to. */
+       int dto_isoc_frame_index;
 
        gfp_t gfp;                      /* allocation mask */
 
        struct wusb_dev *wusb_dev;      /* for activity timestamps */
 };
 
+static void __wa_populate_dto_urb_isoc(struct wa_xfer *xfer,
+       struct wa_seg *seg, int curr_iso_frame);
+
 static inline void wa_xfer_init(struct wa_xfer *xfer)
 {
        kref_init(&xfer->refcnt);
@@ -462,6 +470,31 @@ error_kmalloc:
 
 }
 
+/*
+ * Calculate the number of isoc frames starting from isoc_frame_offset
+ * that will fit a in transfer segment.
+ */
+static int __wa_seg_calculate_isoc_frame_count(struct wa_xfer *xfer,
+       int isoc_frame_offset, int *total_size)
+{
+       int segment_size = 0, frame_count = 0;
+       int index = isoc_frame_offset;
+
+       while ((index < xfer->urb->number_of_packets)
+               && ((segment_size + xfer->urb->iso_frame_desc[index].length)
+                               <= xfer->seg_size)) {
+               /* this frame fits. count it. */
+               ++frame_count;
+               segment_size += xfer->urb->iso_frame_desc[index].length;
+
+               /* move to the next isoc frame. */
+               ++index;
+       }
+
+       *total_size = segment_size;
+       return frame_count;
+}
+
 /*
  *
  * @returns < 0 on error, transfer segment request size if ok
@@ -505,8 +538,20 @@ static ssize_t __wa_xfer_setup_sizes(struct wa_xfer *xfer,
 
        maxpktsize = le16_to_cpu(rpipe->descr.wMaxPacketSize);
        if ((rpipe->descr.bmAttribute & 0x3) == USB_ENDPOINT_XFER_ISOC) {
+               int index = 0;
+
                xfer->seg_size = maxpktsize;
-               xfer->segs = urb->number_of_packets;
+               xfer->segs = 0;
+               /*
+                * loop over urb->number_of_packets to determine how many
+                * xfer segments will be needed to send the isoc frames.
+                */
+               while (index < urb->number_of_packets) {
+                       int seg_size; /* don't care. */
+                       index += __wa_seg_calculate_isoc_frame_count(xfer,
+                                       index, &seg_size);
+                       ++xfer->segs;
+               }
        } else {
                xfer->seg_size = le16_to_cpu(rpipe->descr.wBlocks)
                        * 1 << (xfer->wa->wa_descr->bRPipeBlockSize - 1);
@@ -523,20 +568,43 @@ static ssize_t __wa_xfer_setup_sizes(struct wa_xfer *xfer,
                xfer->seg_size = (xfer->seg_size / maxpktsize) * maxpktsize;
                xfer->segs = DIV_ROUND_UP(urb->transfer_buffer_length,
                                                xfer->seg_size);
-               if (xfer->segs >= WA_SEGS_MAX) {
-                       dev_err(dev, "BUG? oops, number of segments %zu bigger than %d\n",
-                               (urb->transfer_buffer_length/xfer->seg_size),
-                               WA_SEGS_MAX);
-                       result = -EINVAL;
-                       goto error;
-               }
                if (xfer->segs == 0 && *pxfer_type == WA_XFER_TYPE_CTL)
                        xfer->segs = 1;
        }
+
+       if (xfer->segs >= WA_SEGS_MAX) {
+               dev_err(dev, "BUG? oops, number of segments %zu bigger than %d\n",
+                       (urb->transfer_buffer_length/xfer->seg_size),
+                       WA_SEGS_MAX);
+               result = -EINVAL;
+               goto error;
+       }
 error:
        return result;
 }
 
+static void __wa_setup_isoc_packet_descr(
+               struct wa_xfer_packet_info_hwaiso *packet_desc,
+               struct wa_xfer *xfer,
+               struct wa_seg *seg) {
+       struct usb_iso_packet_descriptor *iso_frame_desc =
+               xfer->urb->iso_frame_desc;
+       int frame_index;
+
+       /* populate isoc packet descriptor. */
+       packet_desc->bPacketType = WA_XFER_ISO_PACKET_INFO;
+       packet_desc->wLength = cpu_to_le16(sizeof(*packet_desc) +
+               (sizeof(packet_desc->PacketLength[0]) *
+                       seg->isoc_frame_count));
+       for (frame_index = 0; frame_index < seg->isoc_frame_count;
+               ++frame_index) {
+               int offset_index = frame_index + seg->isoc_frame_offset;
+               packet_desc->PacketLength[frame_index] =
+                       cpu_to_le16(iso_frame_desc[offset_index].length);
+       }
+}
+
+
 /* Fill in the common request header and xfer-type specific data. */
 static void __wa_xfer_setup_hdr0(struct wa_xfer *xfer,
                                 struct wa_xfer_hdr *xfer_hdr0,
@@ -544,8 +612,9 @@ static void __wa_xfer_setup_hdr0(struct wa_xfer *xfer,
                                 size_t xfer_hdr_size)
 {
        struct wa_rpipe *rpipe = xfer->ep->hcpriv;
+       struct wa_seg *seg = xfer->seg[0];
 
-       xfer_hdr0 = &xfer->seg[0]->xfer_hdr;
+       xfer_hdr0 = &seg->xfer_hdr;
        xfer_hdr0->bLength = xfer_hdr_size;
        xfer_hdr0->bRequestType = xfer_type;
        xfer_hdr0->wRPipe = rpipe->descr.wRPipeIndex;
@@ -567,19 +636,11 @@ static void __wa_xfer_setup_hdr0(struct wa_xfer *xfer,
                        container_of(xfer_hdr0, struct wa_xfer_hwaiso, hdr);
                struct wa_xfer_packet_info_hwaiso *packet_desc =
                        ((void *)xfer_iso) + xfer_hdr_size;
-               struct usb_iso_packet_descriptor *iso_frame_desc =
-                       &(xfer->urb->iso_frame_desc[0]);
+
                /* populate the isoc section of the transfer request. */
-               xfer_iso->dwNumOfPackets = cpu_to_le32(1);
-               /*
-                * populate isoc packet descriptor.  This assumes 1
-                * packet per segment.
-                */
-               packet_desc->wLength = cpu_to_le16(sizeof(*packet_desc) +
-                       sizeof(packet_desc->PacketLength[0]));
-               packet_desc->bPacketType = WA_XFER_ISO_PACKET_INFO;
-               packet_desc->PacketLength[0] =
-                       cpu_to_le16(iso_frame_desc->length);
+               xfer_iso->dwNumOfPackets = cpu_to_le32(seg->isoc_frame_count);
+               /* populate isoc packet descriptor. */
+               __wa_setup_isoc_packet_descr(packet_desc, xfer, seg);
                break;
        }
        default:
@@ -608,54 +669,112 @@ static void wa_seg_dto_cb(struct urb *urb)
        struct wa_rpipe *rpipe;
        unsigned long flags;
        unsigned rpipe_ready = 0;
+       int data_send_done = 1, release_dto = 0, holding_dto = 0;
        u8 done = 0;
+       int result;
 
        /* free the sg if it was used. */
        kfree(urb->sg);
        urb->sg = NULL;
 
+       spin_lock_irqsave(&xfer->lock, flags);
+       wa = xfer->wa;
+       dev = &wa->usb_iface->dev;
+       if (usb_pipeisoc(xfer->urb->pipe)) {
+               xfer->dto_isoc_frame_index += 1;
+               if (xfer->dto_isoc_frame_index < seg->isoc_frame_count) {
+                       data_send_done = 0;
+                       holding_dto = 1; /* checked in error cases. */
+                       /*
+                        * if this is the last isoc frame of the segment, we
+                        * can release DTO after sending this frame.
+                        */
+                       if ((xfer->dto_isoc_frame_index + 1) >=
+                               seg->isoc_frame_count)
+                               release_dto = 1;
+               }
+               dev_dbg(dev, "xfer 0x%08X#%u: isoc frame = %d, holding_dto = %d, release_dto = %d.\n",
+                       wa_xfer_id(xfer), seg->index,
+                       xfer->dto_isoc_frame_index, holding_dto, release_dto);
+       }
+       spin_unlock_irqrestore(&xfer->lock, flags);
+
        switch (urb->status) {
        case 0:
                spin_lock_irqsave(&xfer->lock, flags);
-               wa = xfer->wa;
-               dev = &wa->usb_iface->dev;
-               dev_dbg(dev, "xfer %p#%u: data out done (%d bytes)\n",
-                       xfer, seg->index, urb->actual_length);
-               if (seg->status < WA_SEG_PENDING)
-                       seg->status = WA_SEG_PENDING;
-               seg->result = urb->actual_length;
+               seg->result += urb->actual_length;
+               if (data_send_done) {
+                       dev_dbg(dev, "xfer 0x%08X#%u: data out done (%zu bytes)\n",
+                               wa_xfer_id(xfer), seg->index, seg->result);
+                       if (seg->status < WA_SEG_PENDING)
+                               seg->status = WA_SEG_PENDING;
+               } else {
+                       /* should only hit this for isoc xfers. */
+                       /*
+                        * Populate the dto URB with the next isoc frame buffer,
+                        * send the URB and release DTO if we no longer need it.
+                        */
+                        __wa_populate_dto_urb_isoc(xfer, seg,
+                               seg->isoc_frame_offset +
+                               xfer->dto_isoc_frame_index);
+
+                       /* resubmit the URB with the next isoc frame. */
+                       result = usb_submit_urb(seg->dto_urb, GFP_ATOMIC);
+                       if (result < 0) {
+                               dev_err(dev, "xfer 0x%08X#%u: DTO submit failed: %d\n",
+                                      wa_xfer_id(xfer), seg->index, result);
+                               spin_unlock_irqrestore(&xfer->lock, flags);
+                               goto error_dto_submit;
+                       }
+               }
                spin_unlock_irqrestore(&xfer->lock, flags);
+               if (release_dto) {
+                       __wa_dto_put(wa);
+                       wa_check_for_delayed_rpipes(wa);
+               }
                break;
        case -ECONNRESET:       /* URB unlinked; no need to do anything */
        case -ENOENT:           /* as it was done by the who unlinked us */
+               if (holding_dto) {
+                       __wa_dto_put(wa);
+                       wa_check_for_delayed_rpipes(wa);
+               }
                break;
        default:                /* Other errors ... */
-               spin_lock_irqsave(&xfer->lock, flags);
-               wa = xfer->wa;
-               dev = &wa->usb_iface->dev;
-               rpipe = xfer->ep->hcpriv;
-               dev_dbg(dev, "xfer %p#%u: data out error %d\n",
-                       xfer, seg->index, urb->status);
-               if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
-                           EDC_ERROR_TIMEFRAME)){
-                       dev_err(dev, "DTO: URB max acceptable errors "
-                               "exceeded, resetting device\n");
-                       wa_reset_all(wa);
-               }
-               if (seg->status != WA_SEG_ERROR) {
-                       seg->status = WA_SEG_ERROR;
-                       seg->result = urb->status;
-                       xfer->segs_done++;
-                       __wa_xfer_abort(xfer);
-                       rpipe_ready = rpipe_avail_inc(rpipe);
-                       done = __wa_xfer_is_done(xfer);
-               }
-               spin_unlock_irqrestore(&xfer->lock, flags);
-               if (done)
-                       wa_xfer_completion(xfer);
-               if (rpipe_ready)
-                       wa_xfer_delayed_run(rpipe);
+               dev_err(dev, "xfer 0x%08X#%u: data out error %d\n",
+                       wa_xfer_id(xfer), seg->index, urb->status);
+               goto error_default;
+       }
+
+       return;
+
+error_dto_submit:
+error_default:
+       spin_lock_irqsave(&xfer->lock, flags);
+       rpipe = xfer->ep->hcpriv;
+       if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
+                   EDC_ERROR_TIMEFRAME)){
+               dev_err(dev, "DTO: URB max acceptable errors exceeded, resetting device\n");
+               wa_reset_all(wa);
+       }
+       if (seg->status != WA_SEG_ERROR) {
+               seg->status = WA_SEG_ERROR;
+               seg->result = urb->status;
+               xfer->segs_done++;
+               __wa_xfer_abort(xfer);
+               rpipe_ready = rpipe_avail_inc(rpipe);
+               done = __wa_xfer_is_done(xfer);
        }
+       spin_unlock_irqrestore(&xfer->lock, flags);
+       if (holding_dto) {
+               __wa_dto_put(wa);
+               wa_check_for_delayed_rpipes(wa);
+       }
+       if (done)
+               wa_xfer_completion(xfer);
+       if (rpipe_ready)
+               wa_xfer_delayed_run(rpipe);
+
 }
 
 /*
@@ -686,8 +805,8 @@ static void wa_seg_iso_pack_desc_cb(struct urb *urb)
                spin_lock_irqsave(&xfer->lock, flags);
                wa = xfer->wa;
                dev = &wa->usb_iface->dev;
-               dev_dbg(dev, "iso xfer %p#%u: packet descriptor done\n",
-                       xfer, seg->index);
+               dev_dbg(dev, "iso xfer %08X#%u: packet descriptor done\n",
+                       wa_xfer_id(xfer), seg->index);
                if (xfer->is_inbound && seg->status < WA_SEG_PENDING)
                        seg->status = WA_SEG_PENDING;
                spin_unlock_irqrestore(&xfer->lock, flags);
@@ -700,8 +819,8 @@ static void wa_seg_iso_pack_desc_cb(struct urb *urb)
                wa = xfer->wa;
                dev = &wa->usb_iface->dev;
                rpipe = xfer->ep->hcpriv;
-               pr_err_ratelimited("iso xfer %p#%u: packet descriptor error %d\n",
-                               xfer, seg->index, urb->status);
+               pr_err_ratelimited("iso xfer %08X#%u: packet descriptor error %d\n",
+                               wa_xfer_id(xfer), seg->index, urb->status);
                if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
                            EDC_ERROR_TIMEFRAME)){
                        dev_err(dev, "DTO: URB max acceptable errors exceeded, resetting device\n");
@@ -885,8 +1004,8 @@ static struct scatterlist *wa_xfer_create_subset_sg(struct scatterlist *in_sg,
 /*
  * Populate DMA buffer info for the isoc dto urb.
  */
-static void __wa_populate_dto_urb_iso(struct wa_xfer *xfer,
-       struct wa_seg *seg,     int curr_iso_frame)
+static void __wa_populate_dto_urb_isoc(struct wa_xfer *xfer,
+       struct wa_seg *seg, int curr_iso_frame)
 {
        /*
         * dto urb buffer address and size pulled from
@@ -960,13 +1079,14 @@ static int __wa_populate_dto_urb(struct wa_xfer *xfer,
  */
 static int __wa_xfer_setup_segs(struct wa_xfer *xfer, size_t xfer_hdr_size)
 {
-       int result, cnt;
+       int result, cnt, iso_frame_offset;
        size_t alloc_size = sizeof(*xfer->seg[0])
                - sizeof(xfer->seg[0]->xfer_hdr) + xfer_hdr_size;
        struct usb_device *usb_dev = xfer->wa->usb_dev;
        const struct usb_endpoint_descriptor *dto_epd = xfer->wa->dto_epd;
        struct wa_seg *seg;
-       size_t buf_itr, buf_size, buf_itr_size, iso_pkt_descr_size = 0;
+       size_t buf_itr, buf_size, buf_itr_size;
+       int xfer_isoc_frame_offset = 0;
 
        result = -ENOMEM;
        xfer->seg = kcalloc(xfer->segs, sizeof(xfer->seg[0]), GFP_ATOMIC);
@@ -974,24 +1094,30 @@ static int __wa_xfer_setup_segs(struct wa_xfer *xfer, size_t xfer_hdr_size)
                goto error_segs_kzalloc;
        buf_itr = 0;
        buf_size = xfer->urb->transfer_buffer_length;
+       iso_frame_offset = 0;
+       for (cnt = 0; cnt < xfer->segs; cnt++) {
+               size_t iso_pkt_descr_size = 0;
+               int seg_isoc_frame_count = 0, seg_isoc_size = 0;
 
-       if (usb_pipeisoc(xfer->urb->pipe)) {
-               /*
-                * This calculation assumes one isoc packet per xfer segment.
-                * It will need to be updated if this changes.
-                */
-               iso_pkt_descr_size = sizeof(struct wa_xfer_packet_info_hwaiso) +
-                       sizeof(__le16);
-               alloc_size += iso_pkt_descr_size;
-       }
+               if (usb_pipeisoc(xfer->urb->pipe)) {
+                       seg_isoc_frame_count =
+                               __wa_seg_calculate_isoc_frame_count(xfer,
+                                       xfer_isoc_frame_offset, &seg_isoc_size);
 
-       for (cnt = 0; cnt < xfer->segs; cnt++) {
-               seg = xfer->seg[cnt] = kmalloc(alloc_size, GFP_ATOMIC);
+                       iso_pkt_descr_size =
+                               sizeof(struct wa_xfer_packet_info_hwaiso) +
+                               (seg_isoc_frame_count * sizeof(__le16));
+               }
+               seg = xfer->seg[cnt] = kmalloc(alloc_size + iso_pkt_descr_size,
+                                               GFP_ATOMIC);
                if (seg == NULL)
                        goto error_seg_kmalloc;
                wa_seg_init(seg);
                seg->xfer = xfer;
                seg->index = cnt;
+               seg->isoc_frame_count = seg_isoc_frame_count;
+               seg->isoc_frame_offset = xfer_isoc_frame_offset;
+               seg->isoc_size = seg_isoc_size;
                usb_fill_bulk_urb(&seg->tr_urb, usb_dev,
                                  usb_sndbulkpipe(usb_dev,
                                                  dto_epd->bEndpointAddress),
@@ -1029,8 +1155,16 @@ static int __wa_xfer_setup_segs(struct wa_xfer *xfer, size_t xfer_hdr_size)
                                        iso_pkt_descr_size,
                                        wa_seg_iso_pack_desc_cb, seg);
 
-                               /* fill in the xfer buffer information. */
-                               __wa_populate_dto_urb_iso(xfer, seg, cnt);
+                               /*
+                                * Fill in the xfer buffer information for the
+                                * first isoc frame.  Subsequent frames in this
+                                * segment will be filled in and sent from the
+                                * DTO completion routine, if needed.
+                                */
+                               __wa_populate_dto_urb_isoc(xfer, seg,
+                                       xfer_isoc_frame_offset);
+                               /* adjust starting frame offset for next seg. */
+                               xfer_isoc_frame_offset += seg_isoc_frame_count;
                        } else {
                                /* fill in the xfer buffer information. */
                                result = __wa_populate_dto_urb(xfer, seg,
@@ -1099,28 +1233,23 @@ static int __wa_xfer_setup(struct wa_xfer *xfer, struct urb *urb)
        xfer_hdr = xfer_hdr0;
        if (xfer_type == WA_XFER_TYPE_ISO) {
                xfer_hdr0->dwTransferLength =
-                       cpu_to_le32(xfer->urb->iso_frame_desc[0].length);
+                       cpu_to_le32(xfer->seg[0]->isoc_size);
                for (cnt = 1; cnt < xfer->segs; cnt++) {
-                       struct usb_iso_packet_descriptor *iso_frame_desc =
-                               &(xfer->urb->iso_frame_desc[cnt]);
                        struct wa_xfer_packet_info_hwaiso *packet_desc;
+                       struct wa_seg *seg = xfer->seg[cnt];
 
-                       xfer_hdr = &xfer->seg[cnt]->xfer_hdr;
+                       xfer_hdr = &seg->xfer_hdr;
                        packet_desc = ((void *)xfer_hdr) + xfer_hdr_size;
                        /*
-                        * Copy values from the 0th header and isoc packet
-                        * descriptor.  Segment specific values are set below.
+                        * Copy values from the 0th header. Segment specific
+                        * values are set below.
                         */
-                       memcpy(xfer_hdr, xfer_hdr0,
-                               xfer_hdr_size + sizeof(*packet_desc));
+                       memcpy(xfer_hdr, xfer_hdr0, xfer_hdr_size);
                        xfer_hdr->bTransferSegment = cnt;
                        xfer_hdr->dwTransferLength =
-                               cpu_to_le32(iso_frame_desc->length);
-                       /* populate isoc packet descriptor length. */
-                       packet_desc->PacketLength[0] =
-                               cpu_to_le16(iso_frame_desc->length);
-
-                       xfer->seg[cnt]->status = WA_SEG_READY;
+                               cpu_to_le32(seg->isoc_size);
+                       __wa_setup_isoc_packet_descr(packet_desc, xfer, seg);
+                       seg->status = WA_SEG_READY;
                }
        } else {
                transfer_size = urb->transfer_buffer_length;
@@ -1175,6 +1304,13 @@ static int __wa_seg_submit(struct wa_rpipe *rpipe, struct wa_xfer *xfer,
                               __func__, xfer, seg->index, result);
                        goto error_iso_pack_desc_submit;
                }
+               xfer->dto_isoc_frame_index = 0;
+               /*
+                * If this segment contains more than one isoc frame, hold
+                * onto the dto resource until we send all frames.
+                */
+               if (seg->isoc_frame_count > 1)
+                       *dto_done = 0;
        }
        /* submit the out data if this is an out request. */
        if (seg->dto_urb) {
@@ -1196,6 +1332,7 @@ error_iso_pack_desc_submit:
 error_seg_submit:
        seg->status = WA_SEG_ERROR;
        seg->result = result;
+       *dto_done = 1;
        return result;
 }
 
@@ -1306,9 +1443,6 @@ static int __wa_xfer_submit(struct wa_xfer *xfer)
                available = atomic_read(&rpipe->segs_available);
                empty = list_empty(&rpipe->seg_list);
                seg = xfer->seg[cnt];
-               dev_dbg(dev, "xfer %p ID 0x%08X#%u: available %u empty %u (%s)\n",
-                       xfer, wa_xfer_id(xfer), cnt, available, empty,
-                       available == 0 || !empty ? "delayed" : "submitted");
                if (available && empty) {
                        /*
                         * Only attempt to acquire DTO if we have a segment
@@ -1319,6 +1453,9 @@ static int __wa_xfer_submit(struct wa_xfer *xfer)
                                delay_seg = 0;
                                result = __wa_seg_submit(rpipe, xfer, seg,
                                                        &dto_done);
+                               dev_dbg(dev, "xfer %p ID 0x%08X#%u: available %u empty %u submitted\n",
+                                       xfer, wa_xfer_id(xfer), cnt, available,
+                                       empty);
                                if (dto_done)
                                        __wa_dto_put(rpipe->wa);
 
@@ -1330,6 +1467,8 @@ static int __wa_xfer_submit(struct wa_xfer *xfer)
                }
 
                if (delay_seg) {
+                       dev_dbg(dev, "xfer %p ID 0x%08X#%u: available %u empty %u delayed\n",
+                               xfer, wa_xfer_id(xfer), cnt, available,  empty);
                        seg->status = WA_SEG_DELAYED;
                        list_add_tail(&seg->list_node, &rpipe->seg_list);
                }
@@ -2031,29 +2170,19 @@ static void wa_process_iso_packet_status(struct wahc *wa, struct urb *urb)
 {
        struct device *dev = &wa->usb_iface->dev;
        struct wa_xfer_packet_status_hwaiso *packet_status;
+       struct wa_xfer_packet_status_len_hwaiso *status_array;
        struct wa_xfer *xfer;
        unsigned long flags;
        struct wa_seg *seg;
        struct wa_rpipe *rpipe;
        unsigned done = 0;
-       unsigned rpipe_ready = 0;
-       const int expected_size = sizeof(*packet_status) +
-                               sizeof(packet_status->PacketStatus[0]);
+       unsigned rpipe_ready = 0, seg_index;
+       int expected_size;
 
        /* We have a xfer result buffer; check it */
        dev_dbg(dev, "DTI: isoc packet status %d bytes at %p\n",
                urb->actual_length, urb->transfer_buffer);
-       if (urb->actual_length != expected_size) {
-               dev_err(dev, "DTI Error: isoc packet status--bad urb length (%d bytes vs %d needed)\n",
-                       urb->actual_length, expected_size);
-               goto error_parse_buffer;
-       }
        packet_status = (struct wa_xfer_packet_status_hwaiso *)(wa->dti_buf);
-       if (le16_to_cpu(packet_status->wLength) != expected_size) {
-               dev_err(dev, "DTI Error: isoc packet status--bad length %u\n",
-                       le16_to_cpu(packet_status->wLength));
-               goto error_parse_buffer;
-       }
        if (packet_status->bPacketType != WA_XFER_ISO_PACKET_STATUS) {
                dev_err(dev, "DTI Error: isoc packet status--bad type 0x%02x\n",
                        packet_status->bPacketType);
@@ -2070,13 +2199,28 @@ static void wa_process_iso_packet_status(struct wahc *wa, struct urb *urb)
                goto error_bad_seg;
        seg = xfer->seg[wa->dti_isoc_xfer_seg];
        rpipe = xfer->ep->hcpriv;
-
-       /* set urb isoc packet status and length. */
-       xfer->urb->iso_frame_desc[seg->index].status =
-               wa_xfer_status_to_errno(
-               le16_to_cpu(packet_status->PacketStatus[0].PacketStatus));
-       xfer->urb->iso_frame_desc[seg->index].actual_length =
-               le16_to_cpu(packet_status->PacketStatus[0].PacketLength);
+       expected_size = sizeof(*packet_status) +
+                       (sizeof(packet_status->PacketStatus[0]) *
+                       seg->isoc_frame_count);
+       if (urb->actual_length != expected_size) {
+               dev_err(dev, "DTI Error: isoc packet status--bad urb length (%d bytes vs %d needed)\n",
+                       urb->actual_length, expected_size);
+               goto error_bad_seg;
+       }
+       if (le16_to_cpu(packet_status->wLength) != expected_size) {
+               dev_err(dev, "DTI Error: isoc packet status--bad length %u\n",
+                       le16_to_cpu(packet_status->wLength));
+               goto error_bad_seg;
+       }
+       /* isoc packet status and lengths back xfer urb. */
+       status_array = packet_status->PacketStatus;
+       for (seg_index = 0; seg_index < seg->isoc_frame_count; ++seg_index) {
+               xfer->urb->iso_frame_desc[seg->index].status =
+                       wa_xfer_status_to_errno(
+                       le16_to_cpu(status_array[seg_index].PacketStatus));
+               xfer->urb->iso_frame_desc[seg->index].actual_length =
+                       le16_to_cpu(status_array[seg_index].PacketLength);
+       }
 
        if (!xfer->is_inbound) {
                /* OUT transfer, complete it -- */