[PATCH RFC] ath9k-htc: convert EP3 and EP4 back from bulk to int

[Oleksij Rempel]

If usb auto suspend is enabled or system run in to suspend/resume
cycle ath9k-htc adapter will stop to response. It is reproducible on xhci HCs.

Host part of problem:
XHCI do timing calculation based on Transfer Type and bInterval,
immediately after device was detected. Ath9k-htc try to overwrite
this parameters on module probe and some changes in FW,
since we do not initiate usb reset from the driver this changes
are not took to account. So, before any kind of suspend or reset,
host controller will operate with old parameters. Only after suspend/resume
and if interface id stay unchanged, new parameters will by applied. Host
will send bulk data with no intervals (?), which will cause
overflow on FIFO of EP4.

Firmware part of problem:
By default, ath9k-htc adapters configured with EP3 and EP4
as interrupt endpoints. Current firmware will try to overwrite
ConfigDescriptor to make EP3 and EP4 bulk. FIFO for this endpoints
stay not reconfigured, so under the hood it is still Int EP.

Signed-off-by: Oleksij Rempel <linux at rempel-privat.de>
---
 drivers/net/wireless/ath/ath9k/hif_usb.c | 36 ++++++++++----------------------
 1 file changed, 11 insertions(+), 25 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 5205a36..d99ea45 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -115,10 +115,10 @@ static int hif_usb_send_regout(struct hif_device_usb *hif_dev,
 	cmd->skb = skb;
 	cmd->hif_dev = hif_dev;
 
-	usb_fill_bulk_urb(urb, hif_dev->udev,
-			 usb_sndbulkpipe(hif_dev->udev, USB_REG_OUT_PIPE),
+	usb_fill_int_urb(urb, hif_dev->udev,
+			 usb_sndintpipe(hif_dev->udev, USB_REG_OUT_PIPE),
 			 skb->data, skb->len,
-			 hif_usb_regout_cb, cmd);
+			 hif_usb_regout_cb, cmd, 1);
 
 	usb_anchor_urb(urb, &hif_dev->regout_submitted);
 	ret = usb_submit_urb(urb, GFP_KERNEL);
@@ -723,11 +723,11 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb)
 			return;
 		}
 
-		usb_fill_bulk_urb(urb, hif_dev->udev,
-				 usb_rcvbulkpipe(hif_dev->udev,
+		usb_fill_int_urb(urb, hif_dev->udev,
+				 usb_rcvintpipe(hif_dev->udev,
 						 USB_REG_IN_PIPE),
 				 nskb->data, MAX_REG_IN_BUF_SIZE,
-				 ath9k_hif_usb_reg_in_cb, nskb);
+				 ath9k_hif_usb_reg_in_cb, nskb, 1);
 	}
 
 resubmit:
@@ -909,11 +909,11 @@ static int ath9k_hif_usb_alloc_reg_in_urbs(struct hif_device_usb *hif_dev)
 			goto err_skb;
 		}
 
-		usb_fill_bulk_urb(urb, hif_dev->udev,
-				  usb_rcvbulkpipe(hif_dev->udev,
+		usb_fill_int_urb(urb, hif_dev->udev,
+				  usb_rcvintpipe(hif_dev->udev,
 						  USB_REG_IN_PIPE),
 				  skb->data, MAX_REG_IN_BUF_SIZE,
-				  ath9k_hif_usb_reg_in_cb, skb);
+				  ath9k_hif_usb_reg_in_cb, skb, 1);
 
 		/* Anchor URB */
 		usb_anchor_urb(urb, &hif_dev->reg_in_submitted);
@@ -1033,7 +1033,7 @@ static int ath9k_hif_usb_dev_init(struct hif_device_usb *hif_dev)
 {
 	struct usb_host_interface *alt = &hif_dev->interface->altsetting[0];
 	struct usb_endpoint_descriptor *endp;
-	int ret, idx;
+	int ret;
 
 	ret = ath9k_hif_usb_download_fw(hif_dev);
 	if (ret) {
@@ -1043,20 +1043,6 @@ static int ath9k_hif_usb_dev_init(struct hif_device_usb *hif_dev)
 		return ret;
 	}
 
-	/* On downloading the firmware to the target, the USB descriptor of EP4
-	 * is 'patched' to change the type of the endpoint to Bulk. This will
-	 * bring down CPU usage during the scan period.
-	 */
-	for (idx = 0; idx < alt->desc.bNumEndpoints; idx++) {
-		endp = &alt->endpoint[idx].desc;
-		if ((endp->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
-				== USB_ENDPOINT_XFER_INT) {
-			endp->bmAttributes &= ~USB_ENDPOINT_XFERTYPE_MASK;
-			endp->bmAttributes |= USB_ENDPOINT_XFER_BULK;
-			endp->bInterval = 0;
-		}
-	}
-
 	/* Alloc URBs */
 	ret = ath9k_hif_usb_alloc_urbs(hif_dev);
 	if (ret) {
@@ -1268,7 +1254,7 @@ static void ath9k_hif_usb_reboot(struct usb_device *udev)
 	if (!buf)
 		return;
 
-	ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, USB_REG_OUT_PIPE),
+	ret = usb_interrupt_msg(udev, usb_sndintpipe(udev, USB_REG_OUT_PIPE),
 			   buf, 4, NULL, HZ);
 	if (ret)
 		dev_err(&udev->dev, "ath9k_htc: USB reboot failed\n");
-- 
1.8.1.2