The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d53dc38857f6dbefabd9eecfcbf67b6eac9a1ef4 Mon Sep 17 00:00:00 2001
From: Minas Harutyunyan Minas.Harutyunyan@synopsys.com Date: Tue, 20 Jul 2021 05:41:24 -0700 Subject: [PATCH] usb: dwc2: gadget: Fix sending zero length packet in DDMA mode.
Sending zero length packet in DDMA mode perform by DMA descriptor by setting SP (short packet) flag.
For DDMA in function dwc2_hsotg_complete_in() does not need to send zlp.
Tested by USBCV MSC tests.
Fixes: f71b5e2533de ("usb: dwc2: gadget: fix zero length packet transfers") Cc: stable stable@vger.kernel.org Signed-off-by: Minas Harutyunyan Minas.Harutyunyan@synopsys.com Link: https://lore.kernel.org/r/967bad78c55dd2db1c19714eee3d0a17cf99d74a.162677773... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index 74d25019272f..3146df6e6510 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -2749,12 +2749,14 @@ static void dwc2_hsotg_complete_in(struct dwc2_hsotg *hsotg, return; }
- /* Zlp for all endpoints, for ep0 only in DATA IN stage */ + /* Zlp for all endpoints in non DDMA, for ep0 only in DATA IN stage */ if (hs_ep->send_zlp) { - dwc2_hsotg_program_zlp(hsotg, hs_ep); hs_ep->send_zlp = 0; - /* transfer will be completed on next complete interrupt */ - return; + if (!using_desc_dma(hsotg)) { + dwc2_hsotg_program_zlp(hsotg, hs_ep); + /* transfer will be completed on next complete interrupt */ + return; + } }
if (hs_ep->index == 0 && hsotg->ep0_state == DWC2_EP0_DATA_IN) {