usb: gadget: Introduce usb_request->is_last

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@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
This commit is contained in:
Thinh Nguyen 2020-05-05 19:46:13 -07:00 committed by Felipe Balbi
parent 4244ba02ed
commit 5469fd64ef

View file

@ -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;