[PATCH v4 08/13] usb: dwc2: host: Fix toggle reset

[Jules Maselbas]

>From USB 2.0 specification, section 9.4.5:
  ClearFeature(ENDPOINT_HALT) request always results in
  the data toggle being reinitialized to DATA0.

The hacky solution for now is to reset the toggle bit to DATA0 when
the host controller send a ClearFeature request on an endpoint.

Signed-off-by: Jules Maselbas <jmaselbas at kalray.eu>
---
 drivers/usb/dwc2/host.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/usb/dwc2/host.c b/drivers/usb/dwc2/host.c
index 8c116c5df..65fa95162 100644
--- a/drivers/usb/dwc2/host.c
+++ b/drivers/usb/dwc2/host.c
@@ -109,6 +109,14 @@ static void dwc2_hc_init(struct dwc2 *dwc2, uint8_t hc,
 	dwc2_writel(dwc2, 0, HCSPLT(hc));
 }
 
+static void dwc2_endpoint_reset(struct dwc2 *dwc2, int in, int devnum, int ep)
+{
+	if (in)
+		dwc2->in_data_toggle[devnum][ep] = TSIZ_SC_MC_PID_DATA0;
+	else
+		dwc2->out_data_toggle[devnum][ep] = TSIZ_SC_MC_PID_DATA0;
+}
+
 static int wait_for_chhltd(struct dwc2 *dwc2, u8 hc, uint32_t *sub, u8 *tgl)
 {
 	int ret;
@@ -373,7 +381,18 @@ static int dwc2_submit_control_msg(struct usb_device *udev,
 	if (ret)
 		return ret;
 
+	if (setup->requesttype == USB_RECIP_ENDPOINT
+	    && setup->request == USB_REQ_CLEAR_FEATURE) {
+		/* From USB 2.0, section 9.4.5:
+		 * ClearFeature(ENDPOINT_HALT) request always results
+		 * in the data toggle being reinitialized to DATA0.
+		 */
+		int ep = le16_to_cpu(setup->index) & 0xf;
+		dwc2_endpoint_reset(dwc2, usb_pipein(pipe), devnum, ep);
+	}
+
 	udev->act_len = act_len;
+	udev->status = 0;
 
 	return 0;
 }
-- 
2.17.1