3.16.42-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> commit 19ec31230eb3084431bc2e565fd085f79f564274 upstream. Let's call dwc3_ep0_prepare_one_trb() explicitly because there are occasions where we will need more than one TRB to handle an EP0 transfer. A follow-up patch will fix one bug related to multiple-TRB Data Phases when it comes to mapping/unmapping requests for DMA. Reported-by: Janusz Dziedzic <januszx.dziedzic@xxxxxxxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> [bwh: Backported to 3.16: - dwc3_ep0_prepare_one_trb() and dwc3_ep0_start_trans() don't take a 'chain' parameter - Some of the call sites don't exist here - Adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/usb/dwc3/ep0.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) --- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -75,8 +75,7 @@ static void dwc3_ep0_prepare_one_trb(str | DWC3_TRB_CTRL_ISP_IMI); } -static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum, dma_addr_t buf_dma, - u32 len, u32 type) +static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum) { struct dwc3_gadget_ep_cmd_params params; struct dwc3_ep *dep; @@ -86,8 +85,6 @@ static int dwc3_ep0_start_trans(struct d if (dep->flags & DWC3_EP_BUSY) return 0; - dwc3_ep0_prepare_one_trb(dwc, epnum, buf_dma, len, type); - memset(¶ms, 0, sizeof(params)); params.param0 = upper_32_bits(dwc->ep0_trb_addr); params.param1 = lower_32_bits(dwc->ep0_trb_addr); @@ -287,8 +284,9 @@ void dwc3_ep0_out_start(struct dwc3 *dwc { int ret; - ret = dwc3_ep0_start_trans(dwc, 0, dwc->ctrl_req_addr, 8, + dwc3_ep0_prepare_one_trb(dwc, 0, dwc->ctrl_req_addr, 8, DWC3_TRBCTL_CONTROL_SETUP); + ret = dwc3_ep0_start_trans(dwc, 0); WARN_ON(ret < 0); } @@ -897,9 +895,10 @@ static void __dwc3_ep0_do_control_data(s req->direction = !!dep->number; if (req->request.length == 0) { - ret = dwc3_ep0_start_trans(dwc, dep->number, + dwc3_ep0_prepare_one_trb(dwc, dep->number, dwc->ctrl_req_addr, 0, DWC3_TRBCTL_CONTROL_DATA); + ret = dwc3_ep0_start_trans(dwc, dep->number); } else if (!IS_ALIGNED(req->request.length, dep->endpoint.maxpacket) && (dep->number == 0)) { u32 transfer_size; @@ -927,9 +926,10 @@ static void __dwc3_ep0_do_control_data(s * DWC3_EP0_BOUNCE_SIZE we will need two chained * TRBs to handle the transfer. */ - ret = dwc3_ep0_start_trans(dwc, dep->number, + dwc3_ep0_prepare_one_trb(dwc, dep->number, dwc->ep0_bounce_addr, transfer_size, DWC3_TRBCTL_CONTROL_DATA); + ret = dwc3_ep0_start_trans(dwc, dep->number); } else { ret = usb_gadget_map_request(&dwc->gadget, &req->request, dep->number); @@ -938,8 +938,9 @@ static void __dwc3_ep0_do_control_data(s return; } - ret = dwc3_ep0_start_trans(dwc, dep->number, req->request.dma, + dwc3_ep0_prepare_one_trb(dwc, dep->number, req->request.dma, req->request.length, DWC3_TRBCTL_CONTROL_DATA); + ret = dwc3_ep0_start_trans(dwc, dep->number); } WARN_ON(ret < 0); @@ -953,8 +954,9 @@ static int dwc3_ep0_start_control_status type = dwc->three_stage_setup ? DWC3_TRBCTL_CONTROL_STATUS3 : DWC3_TRBCTL_CONTROL_STATUS2; - return dwc3_ep0_start_trans(dwc, dep->number, + dwc3_ep0_prepare_one_trb(dwc, dep->number, dwc->ctrl_req_addr, 0, type); + return dwc3_ep0_start_trans(dwc, dep->number); } static void __dwc3_ep0_do_control_status(struct dwc3 *dwc, struct dwc3_ep *dep)