[PATCH 4.9 089/206] usb: dwc3: ep0: explicitly call dwc3_ep0_prepare_one_trb()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Felipe Balbi <felipe.ba...@linux.intel.com>

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.dzied...@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.ba...@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>


---
 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
@@ -85,8 +85,7 @@ static void dwc3_ep0_prepare_one_trb(str
        trace_dwc3_prepare_trb(dep, trb);
 }
 
-static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum, dma_addr_t buf_dma,
-               u32 len, u32 type, bool chain)
+static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum)
 {
        struct dwc3_gadget_ep_cmd_params params;
        struct dwc3_ep                  *dep;
@@ -98,8 +97,6 @@ static int dwc3_ep0_start_trans(struct d
                return 0;
        }
 
-       dwc3_ep0_prepare_one_trb(dwc, epnum, buf_dma, len, type, chain);
-
        memset(&params, 0, sizeof(params));
        params.param0 = upper_32_bits(dwc->ep0_trb_addr);
        params.param1 = lower_32_bits(dwc->ep0_trb_addr);
@@ -314,8 +311,9 @@ 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, false);
+       ret = dwc3_ep0_start_trans(dwc, 0);
        WARN_ON(ret < 0);
 }
 
@@ -886,9 +884,9 @@ static void dwc3_ep0_complete_data(struc
 
                        dwc->ep0_next_event = DWC3_EP0_COMPLETE;
 
-                       ret = dwc3_ep0_start_trans(dwc, epnum,
-                                       dwc->ctrl_req_addr, 0,
-                                       DWC3_TRBCTL_CONTROL_DATA, false);
+                       dwc3_ep0_prepare_one_trb(dwc, epnum, dwc->ctrl_req_addr,
+                                       0, DWC3_TRBCTL_CONTROL_DATA, false);
+                       ret = dwc3_ep0_start_trans(dwc, epnum);
                        WARN_ON(ret < 0);
                }
        }
@@ -972,9 +970,10 @@ 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, false);
+               ret = dwc3_ep0_start_trans(dwc, dep->number);
        } else if (!IS_ALIGNED(req->request.length, dep->endpoint.maxpacket)
                        && (dep->number == 0)) {
                u32     transfer_size = 0;
@@ -992,7 +991,7 @@ static void __dwc3_ep0_do_control_data(s
                if (req->request.length > DWC3_EP0_BOUNCE_SIZE) {
                        transfer_size = ALIGN(req->request.length - maxpacket,
                                              maxpacket);
-                       ret = dwc3_ep0_start_trans(dwc, dep->number,
+                       dwc3_ep0_prepare_one_trb(dwc, dep->number,
                                                   req->request.dma,
                                                   transfer_size,
                                                   DWC3_TRBCTL_CONTROL_DATA,
@@ -1004,9 +1003,10 @@ static void __dwc3_ep0_do_control_data(s
 
                dwc->ep0_bounced = true;
 
-               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, false);
+               ret = dwc3_ep0_start_trans(dwc, dep->number);
        } else {
                ret = usb_gadget_map_request(&dwc->gadget, &req->request,
                                dep->number);
@@ -1015,9 +1015,10 @@ 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,
                                false);
+               ret = dwc3_ep0_start_trans(dwc, dep->number);
        }
 
        WARN_ON(ret < 0);
@@ -1031,8 +1032,9 @@ 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, false);
+       return dwc3_ep0_start_trans(dwc, dep->number);
 }
 
 static void __dwc3_ep0_do_control_status(struct dwc3 *dwc, struct dwc3_ep *dep)