usb: dwc2: WA for Full speed ISOC IN in DDMA mode.
By clearing NAK status of EP, core will send ZLP
to IN token and assert NAK interrupt relying
on TxFIFO status only.
The WA applies only to core versions from 2.72a
to 4.00a (including both). Also for FS_IOT_1.00a
and HS_IOT_1.00a.
Signed-off-by: Artur Petrosyan <arturp@synopsys.com>
Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 684b4f5..f0d9ccf 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -3945,6 +3945,27 @@ static int dwc2_hsotg_ep_enable(struct usb_ep *ep,
if (index && !hs_ep->isochronous)
epctrl |= DXEPCTL_SETD0PID;
+ /* WA for Full speed ISOC IN in DDMA mode.
+ * By Clear NAK status of EP, core will send ZLP
+ * to IN token and assert NAK interrupt relying
+ * on TxFIFO status only
+ */
+
+ if (hsotg->gadget.speed == USB_SPEED_FULL &&
+ hs_ep->isochronous && dir_in) {
+ /* The WA applies only to core versions from 2.72a
+ * to 4.00a (including both). Also for FS_IOT_1.00a
+ * and HS_IOT_1.00a.
+ */
+ u32 gsnpsid = dwc2_readl(hsotg->regs + GSNPSID);
+
+ if ((gsnpsid >= DWC2_CORE_REV_2_72a &&
+ gsnpsid <= DWC2_CORE_REV_4_00a) ||
+ gsnpsid == DWC2_FS_IOT_REV_1_00a ||
+ gsnpsid == DWC2_HS_IOT_REV_1_00a)
+ epctrl |= DXEPCTL_CNAK;
+ }
+
dev_dbg(hsotg->dev, "%s: write DxEPCTL=0x%08x\n",
__func__, epctrl);