From: Ang Way Chuang Date: Fri, 24 Dec 2010 05:40:46 +0000 (-0300) Subject: [media] cx88-dvb.c: DVB net latency using Hauppauge HVR4000 X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=44c6e2a7c2ec76dd495a0f330f9beac572a2fdd7;p=deliverable%2Flinux.git [media] cx88-dvb.c: DVB net latency using Hauppauge HVR4000 A Hauppauge HVR 4000 is used on a School On Internet Asia (SOI Asia) project in order to carry IP traffic over ULE. However, there is an issue with high latency jitter. My boss, Husni, identified the problem and provided a patch for it. The default buffer size of 32 TS frames on cx88 causes the high latency, so our deployment changes that to 6 TS frames. This patch made the buffer size tunable, while keeping the default buffer size of 32 TS frames unchanged. Signed-off-by: Achmad Husni Thamrin Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/video/cx88/cx88-dvb.c b/drivers/media/video/cx88/cx88-dvb.c index 367a653f4c95..90717ee944ec 100644 --- a/drivers/media/video/cx88/cx88-dvb.c +++ b/drivers/media/video/cx88/cx88-dvb.c @@ -67,6 +67,10 @@ static unsigned int debug; module_param(debug, int, 0644); MODULE_PARM_DESC(debug,"enable debug messages [dvb]"); +static unsigned int dvb_buf_tscnt = 32; +module_param(dvb_buf_tscnt, int, 0644); +MODULE_PARM_DESC(dvb_buf_tscnt, "DVB Buffer TS count [dvb]"); + DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); #define dprintk(level,fmt, arg...) if (debug >= level) \ @@ -80,10 +84,10 @@ static int dvb_buf_setup(struct videobuf_queue *q, struct cx8802_dev *dev = q->priv_data; dev->ts_packet_size = 188 * 4; - dev->ts_packet_count = 32; + dev->ts_packet_count = dvb_buf_tscnt; *size = dev->ts_packet_size * dev->ts_packet_count; - *count = 32; + *count = dvb_buf_tscnt; return 0; }