V4L/DVB (12229): gspca - main: Change the ISOC initialization mechanism.

- call a new subdriver function 'isoc_init' before chosing the first
  alternate setting.
- call a new subdriver function 'isoc_nego' when submitting the URBs failed.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 41 insertions, 19 deletions

diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index b8561dfb6c8c..1cc67ae3bfab 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -512,7 +512,10 @@ static int create_urbs(struct gspca_dev *gspca_dev,
         if (!gspca_dev->cam.bulk) {             /* isoc */
 
                 /* See paragraph 5.9 / table 5-11 of the usb 2.0 spec. */
-                psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+                if (gspca_dev->pkt_size == 0)
+                        psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+                else
+                        psize = gspca_dev->pkt_size;
                 npkt = gspca_dev->cam.npkt;
                 if (npkt == 0)
                         npkt = 32;              /* default value */
@@ -597,13 +600,18 @@ static int gspca_init_transfer(struct gspca_dev *gspca_dev)
         /* set the higher alternate setting and
          * loop until urb submit succeeds */
         gspca_dev->alt = gspca_dev->nbalt;
+        if (gspca_dev->sd_desc->isoc_init) {
+                ret = gspca_dev->sd_desc->isoc_init(gspca_dev);
+                if (ret < 0)
+                        goto out;
+        }
+        ep = get_ep(gspca_dev);
+        if (ep == NULL) {
+                ret = -EIO;
+                goto out;
+        }
         for (;;) {
                 PDEBUG(D_STREAM, "init transfer alt %d", gspca_dev->alt);
-                ep = get_ep(gspca_dev);
-                if (ep == NULL) {
-                        ret = -EIO;
-                        goto out;
-                }
                 ret = create_urbs(gspca_dev, ep);
                 if (ret < 0)
                         goto out;
@@ -628,21 +636,32 @@ static int gspca_init_transfer(struct gspca_dev *gspca_dev)
                 /* submit the URBs */
                 for (n = 0; n < gspca_dev->nurbs; n++) {
                         ret = usb_submit_urb(gspca_dev->urb[n], GFP_KERNEL);
-                        if (ret < 0) {
-                                PDEBUG(D_ERR|D_STREAM,
-                                        "usb_submit_urb [%d] err %d", n, ret);
-                                gspca_dev->streaming = 0;
-                                destroy_urbs(gspca_dev);
-                                if (ret == -ENOSPC) {
-                                        msleep(20);     /* wait for kill
-                                                         * complete */
-                                        break;  /* try the previous alt */
-                                }
-                                goto out;
-                        }
+                        if (ret < 0)
+                                break;
                 }
                 if (ret >= 0)
                         break;
+                PDEBUG(D_ERR|D_STREAM,
+                        "usb_submit_urb alt %d err %d", gspca_dev->alt, ret);
+                gspca_dev->streaming = 0;
+                destroy_urbs(gspca_dev);
+                if (ret != -ENOSPC)
+                        goto out;
+
+                /* the bandwidth is not wide enough
+                 * negociate or try a lower alternate setting */
+                msleep(20);     /* wait for kill complete */
+                if (gspca_dev->sd_desc->isoc_nego) {
+                        ret = gspca_dev->sd_desc->isoc_nego(gspca_dev);
+                        if (ret < 0)
+                                goto out;
+                } else {
+                        ep = get_ep(gspca_dev);
+                        if (ep == NULL) {
+                                ret = -EIO;
+                                goto out;
+                        }
+                }
         }
 out:
         mutex_unlock(&gspca_dev->usb_lock);
diff --git a/drivers/media/video/gspca/gspca.h b/drivers/media/video/gspca/gspca.h
index 46c4effdfcd5..70b1fd830876 100644
--- a/drivers/media/video/gspca/gspca.h
+++ b/drivers/media/video/gspca/gspca.h
@@ -98,9 +98,11 @@ struct sd_desc {
 /* mandatory operations */
         cam_cf_op config;       /* called on probe */
         cam_op init;            /* called on probe and resume */
-        cam_op start;           /* called on stream on */
+        cam_op start;           /* called on stream on after URBs creation */
         cam_pkt_op pkt_scan;
 /* optional operations */
+        cam_op isoc_init;       /* called on stream on before getting the EP */
+        cam_op isoc_nego;       /* called when URB submit failed with NOSPC */
         cam_v_op stopN;         /* called on stream off - main alt */
         cam_v_op stop0;         /* called on stream off & disconnect - alt 0 */
         cam_v_op dq_callback;   /* called when a frame has been dequeued */
@@ -178,6 +180,7 @@ struct gspca_dev {
         __u8 iface;                     /* USB interface number */
         __u8 alt;                       /* USB alternate setting */
         __u8 nbalt;                     /* number of USB alternate settings */
+        u16 pkt_size;                   /* ISOC packet size */
 };
 
 int gspca_dev_probe(struct usb_interface *intf,