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 <sarah.a.sharp@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-mem.c | 9 +++++----
drivers/usb/host/xhci.h | 3 ++-
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index c4b8959..94a8b28 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/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(
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index a2fe0b0..c5d6278 100644
--- a/drivers/usb/host/xhci.h
+++ b/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;
--
1.7.4.1
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