What are preferred BULK stream parameters, .count and .buffersize?
for USB2.0?
for USB1.1?
buffersize, which is URB size, have great effect to system load. For
example 512 bytes generates about 10x more wakeups than 5120. It is
quite clear that 512 is too small for whole DVB stream. I did some test
and looks like all USB2.0 devices I have here allow x512 or x188 sizes.
Heinrich Langos did some measurements and results can be seen here:
http://www.linuxtv.org/wiki/index.php/User:Hlangos
In my understanding we should found some balance between URB size and
transferred stream bandwidth. For example DVB-T stream, when common
transmission parameters are used, is more than 20Mbit/sec.
There is also USB bridge chips which does have two or more different
standard frontends needed different stream bandwidths.
Should we add new module param for override module default?
a800 BULK 7x 4096= 28672
af9005 BULK 10x 4096= 40960 USB1.1 BUGFIX: x512=>x188
af9015 BULK 6x 3072= 3072 BUGFIX: x512=>x188
anysee BULK 8x 512= 4096
ce6230 BULK 6x 512= 3072
cinergyT2 BULK 5x 512= 2560
cxusb BULK 5x 8192= 40960
cxusb BULK 7x 4096= 28672
dib0700 BULK 4x39480=157920 210x188 !!HUGE!!
dibusb-mb BULK 7x 4096= 28672 56x512
dibusb-mc BULK 7x 4096= 28672
digitv BULK 7x 4096= 28672
dtt200u BULK 7x 4096= 28672
dtv5100 BULK 8x 4096= 32768
dw2102 BULK 8x 4096= 32768
gl861 BULK 7x 512= 3584
gp8psk BULK 7x 8192= 57344
m920x BULK 8x 512= 4096
m920x BULK 8x16384=131072 256x512 !!HUGE!!
nova-t-usb2 BULK 7x 4096= 28672
opera1 BULK 10x 4096= 40960
umt-010 BULK 10x 512= 5120
vp702x BULK 10x 4096= 40960
vp7045 BULK 7x 4096= 28672
au6610 ISOC 5 frames 40 size 942
ttusb2 ISOC 5 frames 4 size 942
regards
Antti
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