3 files changed, 43 insertions, 25 deletions

diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index 275f1e936304..0966017ca745 100644
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -72,7 +72,8 @@ u32 em28xx_request_buffers(struct em28xx *dev, u32 count)
         const size_t imagesize = PAGE_ALIGN(dev->frame_size);   /*needs to be page aligned cause the buffers can be mapped individually! */
         void *buff = NULL;
         u32 i;
-        em28xx_coredbg("requested %i buffers with size %zi", count, imagesize);
+        em28xx_coredbg("requested %i buffers with size %zi\n",
+                        count, imagesize);
         if (count > EM28XX_NUM_FRAMES)
                 count = EM28XX_NUM_FRAMES;
 
@@ -676,7 +677,7 @@ static void em28xx_isocIrq(struct urb *urb)
                                 continue;
                         }
                         if (urb->iso_frame_desc[i].actual_length >
-                                                 dev->max_pkt_size) {
+                            urb->iso_frame_desc[i].length) {
                                 em28xx_isocdbg("packet bigger than packet size");
                                 continue;
                         }
@@ -722,8 +723,11 @@ void em28xx_uninit_isoc(struct em28xx *dev)
         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
                 if (dev->urb[i]) {
                         usb_kill_urb(dev->urb[i]);
-                        if (dev->transfer_buffer[i]){
-                                usb_buffer_free(dev->udev,(EM28XX_NUM_PACKETS*dev->max_pkt_size),dev->transfer_buffer[i],dev->urb[i]->transfer_dma);
+                        if (dev->transfer_buffer[i]) {
+                                usb_buffer_free(dev->udev,
+                                                dev->urb[i]->transfer_buffer_length,
+                                                dev->transfer_buffer[i],
+                                                dev->urb[i]->transfer_dma);
                         }
                         usb_free_urb(dev->urb[i]);
                 }
@@ -741,7 +745,10 @@ int em28xx_init_isoc(struct em28xx *dev)
 {
         /* change interface to 3 which allows the biggest packet sizes */
         int i, errCode;
-        const int sb_size = EM28XX_NUM_PACKETS * dev->max_pkt_size;
+        int sb_size;
+
+        em28xx_set_alternate(dev);
+        sb_size = EM28XX_NUM_PACKETS * dev->max_pkt_size;
 
         /* reset streaming vars */
         dev->frame_current = NULL;
@@ -750,7 +757,7 @@ int em28xx_init_isoc(struct em28xx *dev)
         /* allocate urbs */
         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
                 struct urb *urb;
-                int j, k;
+                int j;
                 /* allocate transfer buffer */
                 urb = usb_alloc_urb(EM28XX_NUM_PACKETS, GFP_KERNEL);
                 if (!urb){
@@ -758,7 +765,9 @@ int em28xx_init_isoc(struct em28xx *dev)
                         em28xx_uninit_isoc(dev);
                         return -ENOMEM;
                 }
-                dev->transfer_buffer[i] = usb_buffer_alloc(dev->udev, sb_size, GFP_KERNEL,&urb->transfer_dma);
+                dev->transfer_buffer[i] = usb_buffer_alloc(dev->udev, sb_size,
+                                                           GFP_KERNEL,
+                                                           &urb->transfer_dma);
                 if (!dev->transfer_buffer[i]) {
                         em28xx_errdev
                                         ("unable to allocate %i bytes for transfer buffer %i\n",
@@ -777,16 +786,16 @@ int em28xx_init_isoc(struct em28xx *dev)
                 urb->complete = em28xx_isocIrq;
                 urb->number_of_packets = EM28XX_NUM_PACKETS;
                 urb->transfer_buffer_length = sb_size;
-                for (j = k = 0; j < EM28XX_NUM_PACKETS;
-                                j++, k += dev->max_pkt_size) {
-                        urb->iso_frame_desc[j].offset = k;
-                        urb->iso_frame_desc[j].length =
-                                dev->max_pkt_size;
+                for (j = 0; j < EM28XX_NUM_PACKETS; j++) {
+                        urb->iso_frame_desc[j].offset = j * dev->max_pkt_size;
+                        urb->iso_frame_desc[j].length = dev->max_pkt_size;
                 }
                 dev->urb[i] = urb;
         }
 
         /* submit urbs */
+        em28xx_coredbg("Submitting %d urbs of %d packets (%d each)\n",
+                       EM28XX_NUM_BUFS, EM28XX_NUM_PACKETS, dev->max_pkt_size);
         for (i = 0; i < EM28XX_NUM_BUFS; i++) {
                 errCode = usb_submit_urb(dev->urb[i], GFP_KERNEL);
                 if (errCode) {
@@ -803,22 +812,31 @@ int em28xx_init_isoc(struct em28xx *dev)
 int em28xx_set_alternate(struct em28xx *dev)
 {
         int errCode, prev_alt = dev->alt;
-        dev->alt = alt;
-        if (dev->alt == 0) {
-                int i;
-                for(i=0;i< dev->num_alt; i++)
-                        if(dev->alt_max_pkt_size[i]>dev->alt_max_pkt_size[dev->alt])
-                                dev->alt=i;
-        }
+        int i;
+        unsigned int min_pkt_size = dev->bytesperline+4;
+
+        /* When image size is bigger than a ceirtain value,
+           the frame size should be increased, otherwise, only
+           green screen will be received.
+         */
+        if (dev->frame_size > 720*240*2)
+                min_pkt_size *= 2;
+
+        for (i = 0; i < dev->num_alt; i++)
+                if (dev->alt_max_pkt_size[i] >= min_pkt_size)
+                        break;
+        dev->alt = i;
 
         if (dev->alt != prev_alt) {
+                em28xx_coredbg("minimum isoc packet size: %u (alt=%d)\n",
+                                min_pkt_size, dev->alt);
                 dev->max_pkt_size = dev->alt_max_pkt_size[dev->alt];
-                em28xx_coredbg("setting alternate %d with wMaxPacketSize=%u\n", dev->alt,
-                       dev->max_pkt_size);
+                em28xx_coredbg("setting alternate %d with wMaxPacketSize=%u\n",
+                               dev->alt, dev->max_pkt_size);
                 errCode = usb_set_interface(dev->udev, 0, dev->alt);
                 if (errCode < 0) {
                         em28xx_errdev ("cannot change alternate number to %d (error=%i)\n",
-                                                        dev->alt, errCode);
+                                        dev->alt, errCode);
                         return errCode;
                 }
         }
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index eeda3b2faec8..4abe6701a770 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -1352,8 +1352,6 @@ static int em28xx_v4l2_open(struct inode *inode, struct file *filp)
         filp->private_data = fh;
 
         if (dev->type == V4L2_BUF_TYPE_VIDEO_CAPTURE && dev->users == 0) {
-                em28xx_set_alternate(dev);
-
                 dev->width = norm_maxw(dev);
                 dev->height = norm_maxh(dev);
                 dev->frame_size = dev->width * dev->height * 2;
@@ -1362,6 +1360,7 @@ static int em28xx_v4l2_open(struct inode *inode, struct file *filp)
                 dev->hscale = 0;
                 dev->vscale = 0;
 
+                em28xx_set_alternate(dev);
                 em28xx_capture_start(dev, 1);
                 em28xx_resolution_set(dev);
 
@@ -2129,6 +2128,7 @@ static int em28xx_usb_probe(struct usb_interface *interface,
         snprintf(dev->name, 29, "em28xx #%d", nr);
         dev->devno = nr;
         dev->model = id->driver_info;
+        dev->alt   = -1;
 
         /* Checks if audio is provided by some interface */
         for (i = 0; i < udev->config->desc.bNumInterfaces; i++) {
diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 813c0af458d3..04e0e48ecabe 100644
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -33,7 +33,7 @@
 #define UNSET -1
 
 /* maximum number of em28xx boards */
-#define EM28XX_MAXBOARDS 1 /*FIXME: should be bigger */
+#define EM28XX_MAXBOARDS 4 /*FIXME: should be bigger */
 
 /* maximum number of frames that can be queued */
 #define EM28XX_NUM_FRAMES 5