diff options
| author | Sascha Sommer <saschasommer@freenet.de> | 2008-04-22 14:45:47 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-04-24 14:07:49 -0300 |
| commit | 2c4a07b2da61bcd33f18195ff7f355c5bb285904 (patch) | |
| tree | 8128eb02dabe6cd81cb74d715dec8d2a34f92f09 | |
| parent | 4a24ce3a17ee713056db0a24cf558bd595211302 (diff) | |
V4L/DVB (7331): Fix em2800 altsetting selection
Signed-off-by: Sascha Sommer <saschasommer@freenet.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
| -rw-r--r-- | drivers/media/video/em28xx/em28xx-core.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c index dbea89c115b..4ebef10b572 100644 --- a/drivers/media/video/em28xx/em28xx-core.c +++ b/drivers/media/video/em28xx/em28xx-core.c @@ -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", |