Re: [Bluez-devel] [PATCH] Updated sco flow control feature

Brad Midgley
2006-10-19T17:53:16Z

Fabien

I would like to better document how to try this patch and use it with
the alsa sco plugin. I've started it in

https://help.ubuntu.com/community/BluetoothAudio

Is the sco plugin in our cvs current and will it enable your flow control?

Brad

> After a few very busy months at work i finally had the opportunity to go
> back to my bluez flow control patch i left in the middle of nowhere back
> in May. :-)
> You will find attached an updated version of the patch against
> 2.6.18-mh4, as well as a sample test program that shows the flow control
> stuff is really working.
>
> Major changes compared to previous versions:
> * Packets are queued in the core, and are dequeue from there.
> * Flow control is achieved using high resolution timers. This means the
> code is really HZ independant, and things will even go better when the
> dyntick patch which has been in the air recently will be included in the
> mainline kernel.
> * Fixed a stupid bug that would cause packets to be sent really too
> slowly when HZ was < 1000
> * Should work with HZ = 100, 250, 1000, ... or whatever else. I tested
> with 250 HZ only for now.
> * Wrote a test program, "headsettest". To run this program you will need
> an USB dongle that supports SCO, as well as a
> headset. This program records your own voice for 30 seconds, then plays
> what it recorded in your ears for 30 seconds. Beware : Running it
> without the flow control patch is likely to crash your box !!
> * The patch is cleaner. This is mainly due to the fact i am getting to a
> better understanding of Linux socket layer.DEFAULT_SCO_RXBUFS;
> sk->sk_sndtime