xhci: Fix mult base in endpoint bandwidth info.

The "Mult" bits in the SuperSpeed Endpoint Companion Descriptor are
zero-based, and the xHCI host controller wants them to be zero-based in
the input context.  However, for the bandwidth math, we want them to be
one-based.  Fix this.

Fix the documentation about the endpoint bandwidth mult variable in the
xhci.h file, which says it is zero-based.  Also fix the documentation
about num_packets, which is also one-based, not zero-based.

Signed-off-by: Sarah Sharp <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Sarah Sharp

drivers/usb/host/xhci-mem.c

@@ -1473,11 +1473,12 @@ void xhci_update_bw_info(struct xhci_hcd *xhci,
 			/* Added or changed endpoint */
 			bw_info->ep_interval = CTX_TO_EP_INTERVAL(
 					le32_to_cpu(ep_ctx->ep_info));
-			bw_info->mult = CTX_TO_EP_MULT(
-					le32_to_cpu(ep_ctx->ep_info));
-			/* Number of packets is zero-based in the input context,
-			 * but we want one-based for the interval table.
+			/* Number of packets and mult are zero-based in the
+			 * input context, but we want one-based for the
+			 * interval table.
 			 */
+			bw_info->mult = CTX_TO_EP_MULT(
+					le32_to_cpu(ep_ctx->ep_info)) + 1;
 			bw_info->num_packets = CTX_TO_MAX_BURST(
 					le32_to_cpu(ep_ctx->ep_info2)) + 1;
 			bw_info->max_packet_size = MAX_PACKET_DECODED(

drivers/usb/host/xhci.h

@@ -747,8 +747,9 @@ struct xhci_stream_info {
  * (DMI) also limits the total bandwidth (across all domains) that can be used.
  */
 struct xhci_bw_info {
+	/* ep_interval is zero-based */
 	unsigned int		ep_interval;
-	/* mult and num_packets are zero-based */
+	/* mult and num_packets are one-based */
 	unsigned int		mult;
 	unsigned int		num_packets;
 	unsigned int		max_packet_size;