To take advantage of DWC3 internal TRB prefetch and cache for
performance, inform the controller the last request with stream_id
before switching to a different stream transfer. This allows the
controller to maintain its transfer burst within the stream ID.
Introduce the usb-request is_last field to help inform the DWC3
controller of this.
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
---
include/linux/usb/gadget.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index e959c09a97c9..281eabae7f33 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -42,6 +42,8 @@ struct usb_ep;
* @num_mapped_sgs: number of SG entries mapped to DMA (internal)
* @length: Length of that data
* @stream_id: The stream id, when USB3.0 bulk streams are being used
+ * @is_last: Indicates if this is the last request of a stream_id before
+ * switching to a different stream (required for DWC3 controllers).
* @no_interrupt: If true, hints that no completion irq is needed.
* Helpful sometimes with deep request queues that are handled
* directly by DMA controllers.
@@ -104,6 +106,7 @@ struct usb_request {
unsigned num_mapped_sgs;
unsigned stream_id:16;
+ unsigned is_last:1;
unsigned no_interrupt:1;
unsigned zero:1;
unsigned short_not_ok:1;
--
2.11.0
