[PATCH 4/8] usb: cdns3: gadget: add CHAIN and ISP bit for sg list use case

[Peter Chen <peter.chen@nxp.com>]

For sg buffer list use case, we need to add ISP for each TRB, and
add CHAIN bit for each TRB except for the last TRB.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
 drivers/usb/cdns3/gadget.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 25e3ff1cdf61..a308a694abc5 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -1221,8 +1221,14 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep,
 		else
 			priv_req->trb->control = cpu_to_le32(control);
 
-		if (sg_supported)
+		if (sg_supported) {
+			trb->control |= TRB_ISP;
+			/* Don't set chain bit for last TRB */
+			if (sg_iter < num_trb - 1)
+				trb->control |= TRB_CHAIN;
+
 			s = sg_next(s);
+		}
 
 		control = 0;
 		++sg_iter;
-- 
2.17.1