USB: cdc-acm: work around some broken devices

This patch introduces a work around for cdc-acm devices which are
low speed contrary to the specification, which requires bulk endpoints
which are banned in low speed and converted by usbcore to virtual
interrupt endpoints if they are used nevertheless.

Signed-off-by: Arseniy Lartsev <[email protected]>
Cc: Oliver Neukum <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

1 files changed, 23 insertions, 8 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 3f1045993474..5b15d9d8896b 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -387,6 +387,7 @@ static void acm_rx_tasklet(unsigned long _acm)
 	struct acm_ru *rcv;
 	unsigned long flags;
 	unsigned char throttled;
+	struct usb_host_endpoint *ep;
 
 	dbg("Entering acm_rx_tasklet");
 
@@ -462,11 +463,20 @@ urbs:
 
 		rcv->buffer = buf;
 
-		usb_fill_bulk_urb(rcv->urb, acm->dev,
-				  acm->rx_endpoint,
-				  buf->base,
-				  acm->readsize,
-				  acm_read_bulk, rcv);
+		ep = (usb_pipein(acm->rx_endpoint) ? acm->dev->ep_in : acm->dev->ep_out)
+				[usb_pipeendpoint(acm->rx_endpoint)];
+		if (usb_endpoint_xfer_int(&ep->desc))
+			usb_fill_int_urb(rcv->urb, acm->dev,
+					 acm->rx_endpoint,
+					 buf->base,
+					 acm->readsize,
+					 acm_read_bulk, rcv, ep->desc.bInterval);
+		else
+			usb_fill_bulk_urb(rcv->urb, acm->dev,
+					  acm->rx_endpoint,
+					  buf->base,
+					  acm->readsize,
+					  acm_read_bulk, rcv);
 		rcv->urb->transfer_dma = buf->dma;
 		rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
@@ -1227,9 +1237,14 @@ made_compressed_probe:
 			goto alloc_fail7;
 		}
 
-		usb_fill_bulk_urb(snd->urb, usb_dev,
-			usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
-			NULL, acm->writesize, acm_write_bulk, snd);
+		if (usb_endpoint_xfer_int(epwrite))
+			usb_fill_int_urb(snd->urb, usb_dev,
+				usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
+				NULL, acm->writesize, acm_write_bulk, snd, epwrite->bInterval);
+		else
+			usb_fill_bulk_urb(snd->urb, usb_dev,
+				usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
+				NULL, acm->writesize, acm_write_bulk, snd);
 		snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 		snd->instance = acm;
 	}