V4L/DVB (13327): em28xx: fix alt modprobe parameter

It seems that some patch broke alt modprobe parameter. Fix it to allow
changing alternate interfaces during module load and at runtime.

If changed during runtime, you'll need to stop a and restart stream for
the parameter to be used.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index a88257a7d94ffeaee476669a8ddd154d4ddcc12b..33586004eb4438edec8df5eae2c2bdb4f6b3d69e 100644 (file)
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -50,7 +50,7 @@ MODULE_PARM_DESC(reg_debug, "enable debug messages [URB reg]");
                printk(KERN_INFO "%s %s :"fmt, \
                         dev->name, __func__ , ##arg); } while (0)
 
-static int alt = EM28XX_PINOUT;
+static int alt;
 module_param(alt, int, 0644);
 MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");
 
@@ -778,6 +778,16 @@ int em28xx_set_alternate(struct em28xx *dev)
        int i;
        unsigned int min_pkt_size = dev->width * 2 + 4;
 
+       /*
+        * alt = 0 is used only for control messages, so, only values
+        * greater than 0 can be used for streaming.
+        */
+       if (alt && alt < dev->num_alt) {
+               em28xx_coredbg("alternate forced to %d\n", dev->alt);
+               dev->alt = alt;
+               goto set_alt;
+       }
+
        /* When image size is bigger than a certain value,
           the frame size should be increased, otherwise, only
           green screen will be received.
@@ -798,6 +808,7 @@ int em28xx_set_alternate(struct em28xx *dev)
                        dev->alt = i;
        }
 
+set_alt:
        if (dev->alt != prev_alt) {
                em28xx_coredbg("minimum isoc packet size: %u (alt=%d)\n",
                                min_pkt_size, dev->alt);

diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index a476f7bb7bf8f36e5b7852be19d8432c105deccb..bca5cbb7931c0943da68c79467009be0bf736a1f 100644 (file)
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -143,9 +143,6 @@
  */
 #define EM28XX_NUM_PACKETS 40
 
-/* default alternate; 0 means choose the best */
-#define EM28XX_PINOUT 0
-
 #define EM28XX_INTERLACED_DEFAULT 1
 
 /*