USB: whci-hcd: support urbs with scatter-gather lists
Support urbs with scatter-gather lists by trying to fit sg list elements
into page lists in one or more qTDs. qTDs must end on a wMaxPacketSize
boundary so if this isn't possible the urb's sg list must be copied into
bounce buffers.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/whci/whcd.h b/drivers/usb/host/whci/whcd.h
index 24e94d9..c80c7d9 100644
--- a/drivers/usb/host/whci/whcd.h
+++ b/drivers/usb/host/whci/whcd.h
@@ -84,6 +84,11 @@
* @len: the length of data in the associated TD.
* @ntds_remaining: number of TDs (starting from this one) in this transfer.
*
+ * @bounce_buf: a bounce buffer if the std was from an urb with a sg
+ * list that could not be mapped to qTDs directly.
+ * @bounce_sg: the first scatterlist element bounce_buf is for.
+ * @bounce_offset: the offset into bounce_sg for the start of bounce_buf.
+ *
* Queued URBs may require more TDs than are available in a qset so we
* use a list of these "software TDs" (sTDs) to hold per-TD data.
*/
@@ -97,6 +102,10 @@
int num_pointers;
dma_addr_t dma_addr;
struct whc_page_list_entry *pl_virt;
+
+ void *bounce_buf;
+ struct scatterlist *bounce_sg;
+ unsigned bounce_offset;
};
/**