[PATCH 4.9 088/206] usb: dwc3: ep0: add dwc3_ep0_prepare_one_trb()

From: Greg Kroah-Hartman
Date: Tue Jan 10 2017 - 08:47:46 EST


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

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

From: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>

commit 7931ec86c1b738e4e90e58c6d95e5f720d45ee56 upstream.

For now this is just a cleanup patch, no functional
changes. We will be using the new function to fix a
bug introduced long ago by commit 0416e494ce7d
("usb: dwc3: ep0: correct cache sync issue in case
of ep0_bounced") and further worsened by commit
c0bd5456a470 ("usb: dwc3: ep0: handle non maxpacket
aligned transfers > 512")

Reported-by: Janusz Dziedzic <januszx.dziedzic@xxxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>


---
drivers/usb/dwc3/ep0.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)

--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -55,20 +55,13 @@ static const char *dwc3_ep0_state_string
}
}

-static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum, dma_addr_t buf_dma,
- u32 len, u32 type, bool chain)
+static void dwc3_ep0_prepare_one_trb(struct dwc3 *dwc, u8 epnum,
+ dma_addr_t buf_dma, u32 len, u32 type, bool chain)
{
- struct dwc3_gadget_ep_cmd_params params;
struct dwc3_trb *trb;
struct dwc3_ep *dep;

- int ret;
-
dep = dwc->eps[epnum];
- if (dep->flags & DWC3_EP_BUSY) {
- dwc3_trace(trace_dwc3_ep0, "%s still busy", dep->name);
- return 0;
- }

trb = &dwc->ep0_trb[dep->trb_enqueue];

@@ -89,15 +82,28 @@ static int dwc3_ep0_start_trans(struct d
trb->ctrl |= (DWC3_TRB_CTRL_IOC
| DWC3_TRB_CTRL_LST);

- if (chain)
+ 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)
+{
+ struct dwc3_gadget_ep_cmd_params params;
+ struct dwc3_ep *dep;
+ int ret;
+
+ dep = dwc->eps[epnum];
+ if (dep->flags & DWC3_EP_BUSY) {
+ dwc3_trace(trace_dwc3_ep0, "%s still busy", dep->name);
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);

- trace_dwc3_prepare_trb(dep, trb);
-
ret = dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_STARTTRANSFER, &params);
if (ret < 0) {
dwc3_trace(trace_dwc3_ep0, "%s STARTTRANSFER failed",