-static int ohci_queue_iso_receive_dualbuffer(struct fw_iso_context *base,
- struct fw_iso_packet *packet,
- struct fw_iso_buffer *buffer,
- unsigned long payload)
-{
- struct iso_context *ctx = container_of(base, struct iso_context, base);
- struct db_descriptor *db = NULL;
- struct descriptor *d;
- struct fw_iso_packet *p;
- dma_addr_t d_bus, page_bus;
- u32 z, header_z, length, rest;
- int page, offset, packet_count, header_size;
-
- /*
- * FIXME: Cycle lost behavior should be configurable: lose
- * packet, retransmit or terminate..
- */
-
- p = packet;
- z = 2;
-
- /*
- * The OHCI controller puts the isochronous header and trailer in the
- * buffer, so we need at least 8 bytes.
- */
- packet_count = p->header_length / ctx->base.header_size;
- header_size = packet_count * max(ctx->base.header_size, (size_t)8);
-
- /* Get header size in number of descriptors. */
- header_z = DIV_ROUND_UP(header_size, sizeof(*d));
- page = payload >> PAGE_SHIFT;
- offset = payload & ~PAGE_MASK;
- rest = p->payload_length;
- /*
- * The controllers I've tested have not worked correctly when
- * second_req_count is zero. Rather than do something we know won't
- * work, return an error
- */
- if (rest == 0)
- return -EINVAL;
-
- while (rest > 0) {
- d = context_get_descriptors(&ctx->context,
- z + header_z, &d_bus);
- if (d == NULL)
- return -ENOMEM;
-
- db = (struct db_descriptor *) d;
- db->control = cpu_to_le16(DESCRIPTOR_STATUS |
- DESCRIPTOR_BRANCH_ALWAYS);
- db->first_size =
- cpu_to_le16(max(ctx->base.header_size, (size_t)8));
- if (p->skip && rest == p->payload_length) {
- db->control |= cpu_to_le16(DESCRIPTOR_WAIT);
- db->first_req_count = db->first_size;
- } else {
- db->first_req_count = cpu_to_le16(header_size);
- }
- db->first_res_count = db->first_req_count;
- db->first_buffer = cpu_to_le32(d_bus + sizeof(*db));
-
- if (p->skip && rest == p->payload_length)
- length = 4;
- else if (offset + rest < PAGE_SIZE)
- length = rest;
- else
- length = PAGE_SIZE - offset;
-
- db->second_req_count = cpu_to_le16(length);
- db->second_res_count = db->second_req_count;
- page_bus = page_private(buffer->pages[page]);
- db->second_buffer = cpu_to_le32(page_bus + offset);
-
- if (p->interrupt && length == rest)
- db->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
-
- context_append(&ctx->context, d, z, header_z);
- offset = (offset + length) & ~PAGE_MASK;
- rest -= length;
- if (offset == 0)
- page++;
- }
-
- return 0;
-}
-