sound: Improve /dev/sndstat channel info readability

[christos]

Summary

Sponsored by: The FreeBSD Foundation
MFC after: 2 days

Test Plan

# cat /dev/sndstat
FreeBSD Audio Driver
Installed devices:
pcm0: <Dummy Audio Device> on nexus0 (1p:1v/1r:1v) default
        snddev flags=0x2e6<AUTOVCHAN,SOFTPCMVOL,BUSY,MPSAFE,REGISTERED,VPC>
        [dsp0.play.0]: spd 48000, fmt 0x00200010, flags 0x00002100, 0x00000004
                interrupts 0, underruns 0, feed 0, ready 0
                [b:2048/1024/2|bs:2048/1024/2]
                channel flags=0x2100<BUSY,HAS_VCHAN>
                {userland} -> feeder_mixer(0x00200010) -> {hardware}
        dsp0.play.0[dsp0.virtual_play.0]: spd 8000, fmt 0x00100008, flags 0x10000000, 0x00000000
                interrupts 0, underruns 0, feed 0, ready 0
                [b:0/0/0|bs:0/0/0]
                channel flags=0x10000000<VIRTUAL>
                {userland} -> feeder_root(0x00000000) -> {dsp0.play.0}
        [dsp0.record.0]: spd 48000, fmt 0x00200010, flags 0x00002100, 0x00000005
                interrupts 0, overruns 0, feed 0, hfree 2048, sfree 2048
                [b:2048/1024/2|bs:2048/1024/2]
                channel flags=0x2100<BUSY,HAS_VCHAN>
                {hardware} -> feeder_root(0x00200010) -> feeder_mixer(0x00200010) -> {userland}
        dsp0.record.0[dsp0.virtual_record.0]: spd 8000, fmt 0x00100008, flags 0x10000000, 0x00000000
                interrupts 0, overruns 0, feed 0, hfree 0, sfree 0
                [b:0/0/0|bs:0/0/0]
                channel flags=0x10000000<VIRTUAL>
                {dsp0.record.0} -> feeder_root(0x00000000) -> {userland}

[zlei]

I'd recommend to add test plan to do a quick demonstration for the good effect of this change. Then it will help reviewing.

[christos]

Any comments?

[zlei]

No objection from me, since those are verbose message that is mostly useful for debugging.

[dev_submerge.ch]

I'd prefer a smaller indent, maybe 2 spaces instead of the 8 space standard tabs, also for the first indent level. As is, the lines regularly exceed 80 character screen width and break the visual indent with the overflow.
But this is already an improvement, thanks!

[christos]

In D46857#1069256, @dev_submerge.ch wrote:

I'd prefer a smaller indent, maybe 2 spaces instead of the 8 space standard tabs, also for the first indent level. As is, the lines regularly exceed 80 character screen width and break the visual indent with the overflow.
But this is already an improvement, thanks!

The 80 characters will be easily exceeded by the feeder lines even with 2 spaces for all indent levels. I do not really have a big objection to using 2-space indentation, but I do think the 1-tab one looks cleaner.

[dev_submerge.ch]

In D46857#1069572, @christos wrote:

In D46857#1069256, @dev_submerge.ch wrote:

I'd prefer a smaller indent, maybe 2 spaces instead of the 8 space standard tabs, also for the first indent level. As is, the lines regularly exceed 80 character screen width and break the visual indent with the overflow.
But this is already an improvement, thanks!

The 80 characters will be easily exceeded by the feeder lines even with 2 spaces for all indent levels. I do not really have a big objection to using 2-space indentation, but I do think the 1-tab one looks cleaner.

The feeder line may overflow anyway, true, depending on the number of stages. But currently already the interrupt / buffer line exceeds 80 characters, which hurts the visual perception of indenting. Maybe we could also put the buffer info on separate line, as an alternative.

[christos]

Split buffer line as well.

[dev_submerge.ch]

I suppose I'll never get used to 8-width indents ;-)
Anyway, for me this is good to go, thanks!

[christos]

Committed.