From: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> stable inclusion from linux-4.19.199 commit ba176c1bd7ca3e9f3bec70f2637c17d2b86469d1 -------------------------------- commit d53dc38857f6dbefabd9eecfcbf67b6eac9a1ef4 upstream. 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> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/usb/dwc2/gadget.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index d0edb7e453c07..7fff96dff0a03 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -2645,12 +2645,14 @@ 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) { -- 2.25.1