diff options
Diffstat (limited to 'drivers/media/video/em28xx/em28xx-core.c')
| -rw-r--r-- | drivers/media/video/em28xx/em28xx-core.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c index c1caaa855b99..4ebef10b5722 100644 --- a/drivers/media/video/em28xx/em28xx-core.c +++ b/drivers/media/video/em28xx/em28xx-core.c @@ -31,7 +31,7 @@ /* #define ENABLE_DEBUG_ISOC_FRAMES */ -static unsigned int core_debug = 0; +static unsigned int core_debug; module_param(core_debug,int,0644); MODULE_PARM_DESC(core_debug,"enable debug messages [core]"); @@ -40,7 +40,7 @@ MODULE_PARM_DESC(core_debug,"enable debug messages [core]"); printk(KERN_INFO "%s %s :"fmt, \ dev->name, __FUNCTION__ , ##arg); } while (0) -static unsigned int reg_debug = 0; +static unsigned int reg_debug; module_param(reg_debug,int,0644); MODULE_PARM_DESC(reg_debug,"enable debug messages [URB reg]"); @@ -49,7 +49,7 @@ MODULE_PARM_DESC(reg_debug,"enable debug messages [URB reg]"); printk(KERN_INFO "%s %s :"fmt, \ dev->name, __FUNCTION__ , ##arg); } while (0) -static unsigned int isoc_debug = 0; +static unsigned int isoc_debug; module_param(isoc_debug,int,0644); MODULE_PARM_DESC(isoc_debug,"enable debug messages [isoc transfers]"); @@ -813,19 +813,27 @@ int em28xx_set_alternate(struct em28xx *dev) { int errCode, prev_alt = dev->alt; int i; - unsigned int min_pkt_size = dev->bytesperline+4; + unsigned int min_pkt_size = dev->bytesperline + 4; - /* When image size is bigger than a ceirtain value, + /* When image size is bigger than a certain 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) + for (i = 0; i < dev->num_alt; i++) { + /* stop when the selected alt setting offers enough bandwidth */ + if (dev->alt_max_pkt_size[i] >= min_pkt_size) { + dev->alt = i; break; - dev->alt = i; + /* otherwise make sure that we end up with the maximum bandwidth + because the min_pkt_size equation might be wrong... + */ + } else if (dev->alt_max_pkt_size[i] > + dev->alt_max_pkt_size[dev->alt]) + dev->alt = i; + } if (dev->alt != prev_alt) { em28xx_coredbg("minimum isoc packet size: %u (alt=%d)\n", |