[media] em28xx: improve USB endpoint logic, also use bulk transfers

The current enpoint logic ignores all bulk endpoints and uses
a fixed mapping between endpint addresses and the supported
data stream types (analog/audio/DVB):
  Ep 0x82, isoc	=> analog
  Ep 0x83, isoc	=> audio
  Ep 0x84, isoc	=> DVB
Now that the code can also do bulk transfers, the endpoint
logic has to be extended to also consider bulk endpoints.
The new logic preserves backwards compatibility and reflects
the endpoint configurations we have seen so far:
  Ep 0x82, isoc		=> analog
  Ep 0x82, bulk		=> analog
  Ep 0x83, isoc*	=> audio
  Ep 0x84, isoc		=> digital
  Ep 0x84, bulk		=> analog or digital**
 (*: audio should always be isoc)
 (**: analog, if ep 0x82 is isoc, otherwise digital)

[mchehab@redhat.com: Fix a CodingStyle issue: don't break strings
 into separate lines]

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 77 insertions, 18 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index 873b52f71ab..a6f00181c24 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -6,6 +6,7 @@
 		      Markus Rechberger <mrechberger@gmail.com>
 		      Mauro Carvalho Chehab <mchehab@infradead.org>
 		      Sascha Sommer <saschasommer@freenet.de>
+   Copyright (C) 2012 Frank Schäfer <fschaefer.oss@googlemail.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -3209,26 +3210,67 @@ static int em28xx_usb_probe(struct usb_interface *interface,
 			if (udev->speed == USB_SPEED_HIGH)
 				size = size * hb_mult(sizedescr);
 
-			if (usb_endpoint_xfer_isoc(e) &&
-			    usb_endpoint_dir_in(e)) {
+			if (usb_endpoint_dir_in(e)) {
 				switch (e->bEndpointAddress) {
-				case EM28XX_EP_AUDIO:
-					has_audio = true;
-					break;
-				case EM28XX_EP_ANALOG:
+				case 0x82:
 					has_video = true;
-					dev->alt_max_pkt_size_isoc[i] = size;
+					if (usb_endpoint_xfer_isoc(e)) {
+						dev->analog_ep_isoc =
+							    e->bEndpointAddress;
+						dev->alt_max_pkt_size_isoc[i] = size;
+					} else if (usb_endpoint_xfer_bulk(e)) {
+						dev->analog_ep_bulk =
+							    e->bEndpointAddress;
+					}
+					break;
+				case 0x83:
+					if (usb_endpoint_xfer_isoc(e)) {
+						has_audio = true;
+					} else {
+						printk(KERN_INFO DRIVER_NAME
+						": error: skipping audio endpoint 0x83, because it uses bulk transfers !\n");
+					}
 					break;
-				case EM28XX_EP_DIGITAL:
-					has_dvb = true;
-					if (size > dev->dvb_max_pkt_size_isoc) {
-						dev->dvb_max_pkt_size_isoc =
-									  size;
-						dev->dvb_alt_isoc = i;
+				case 0x84:
+					if (has_video &&
+					    (usb_endpoint_xfer_bulk(e))) {
+						dev->analog_ep_bulk =
+							    e->bEndpointAddress;
+					} else {
+						has_dvb = true;
+						if (usb_endpoint_xfer_isoc(e)) {
+							dev->dvb_ep_isoc = e->bEndpointAddress;
+							if (size > dev->dvb_max_pkt_size_isoc) {
+								dev->dvb_max_pkt_size_isoc = size;
+								dev->dvb_alt_isoc = i;
+							}
+						} else {
+							dev->dvb_ep_bulk = e->bEndpointAddress;
+						}
 					}
 					break;
 				}
 			}
+			/* NOTE:
+			 * Old logic with support for isoc transfers only was:
+			 *  0x82	isoc		=> analog
+			 *  0x83	isoc		=> audio
+			 *  0x84	isoc		=> digital
+			 *
+			 * New logic with support for bulk transfers
+			 *  0x82	isoc		=> analog
+			 *  0x82	bulk		=> analog
+			 *  0x83	isoc*		=> audio
+			 *  0x84	isoc		=> digital
+			 *  0x84	bulk		=> analog or digital**
+			 * (*: audio should always be isoc)
+			 * (**: analog, if ep 0x82 is isoc, otherwise digital)
+			 *
+			 * The new logic preserves backwards compatibility and
+			 * reflects the endpoint configurations we have seen
+			 * so far. But there might be devices for which this
+			 * logic is not sufficient...
+			 */
 		}
 	}
 
@@ -3289,6 +3331,12 @@ static int em28xx_usb_probe(struct usb_interface *interface,
 		goto err_free;
 	}
 
+	/* Select USB transfer types to use */
+	if (has_video && !dev->analog_ep_isoc)
+		dev->analog_xfer_bulk = 1;
+	if (has_dvb && !dev->dvb_ep_isoc)
+		dev->dvb_xfer_bulk = 1;
+
 	snprintf(dev->name, sizeof(dev->name), "em28xx #%d", nr);
 	dev->devno = nr;
 	dev->model = id->driver_info;
@@ -3323,12 +3371,23 @@ static int em28xx_usb_probe(struct usb_interface *interface,
 	}
 
 	if (has_dvb) {
-		/* pre-allocate DVB isoc transfer buffers */
-		retval = em28xx_alloc_urbs(dev, EM28XX_DIGITAL_MODE, 0,
-					   EM28XX_DVB_NUM_BUFS,
-					   dev->dvb_max_pkt_size_isoc,
-					   EM28XX_DVB_NUM_ISOC_PACKETS);
+		/* pre-allocate DVB usb transfer buffers */
+		if (dev->dvb_xfer_bulk) {
+			retval = em28xx_alloc_urbs(dev, EM28XX_DIGITAL_MODE,
+					    dev->dvb_xfer_bulk,
+					    EM28XX_DVB_NUM_BUFS,
+					    512,
+					    EM28XX_DVB_BULK_PACKET_MULTIPLIER);
+		} else {
+			retval = em28xx_alloc_urbs(dev, EM28XX_DIGITAL_MODE,
+					    dev->dvb_xfer_bulk,
+					    EM28XX_DVB_NUM_BUFS,
+					    dev->dvb_max_pkt_size_isoc,
+					    EM28XX_DVB_NUM_ISOC_PACKETS);
+		}
 		if (retval) {
+			printk(DRIVER_NAME
+			       ": Failed to pre-allocate USB transfer buffers for DVB.\n");
 			goto unlock_and_free;
 		}
 	}