sound: Retire DSP_DEFAULT_SPEED

[christos]

Summary

Only a few drivers use this, but this is not really our "default" speed.
And even those drivers most likely override that value at some point
once CHANNEL_SETSPEED() has been called.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

[markj]

Why not rename the constant to something more suitable? Why is 8000 used in these drivers as the initial value?

[christos]

In D53562#1223161, @markj wrote:

Why not rename the constant to something more suitable? Why is 8000 used in these drivers as the initial value?

I do not know why they use it as the initial value, and I'm a bit reluctant to change it to something more reasonable (44100), because I do not own these cards in order to test. My guess is what I explain in the commit message: they probably set it as a dummy value (along with the u8 format), and it gets immediately changed once CHANNEL_SETSPEED() and CHANNEL_SETFORMAT() are called when the card is properly initialized.

[emaste]

8kHz is (was?) the default if you just dumped data into /dev/dsp without any sound ioctls, e.g. cat /bin/ls > /dev/dsp

[christos]

In D53562#1223195, @emaste wrote:

8kHz is (was?) the default if you just dumped data into /dev/dsp without any sound ioctls, e.g. cat /bin/ls > /dev/dsp

It was. I changed this in e89ee05b7cf1a ("sound: Initialize channels with sane default rate and format").