From: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx> Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/967bad78c55dd2db1c19714eee3d0a17cf99d74a.1626777738.git.Minas.Harutyunyan@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/dwc2/gadget.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -2749,12 +2749,14 @@ static void dwc2_hsotg_complete_in(struc 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) {