mixer(3): temporary fix in mixer_open()

[christos]

Summary

This patch fixes the case where m->unit = -1 (when we pass
a /dev/dsp<N>.vp<N> device), which results in mixer(8) not
printing any info about the device (audio card name, ...).

Note this is a temporary patch until a more elegant solution is
found.

[• hselasky]

Why do you need to do a strdup() when you are not writing the string? Or did I miss something?

lib/libmixer/mixer.c

135

free() already has a NULL check.

[• hselasky]

What about virtual_oss in ports? It can create any such device ....

[christos]

In D32236#727412, @hselasky wrote:

Why do you need to do a strdup() when you are not writing the string? Or did I miss something?

Fixed.

[christos]

In D32236#727414, @hselasky wrote:

What about virtual_oss in ports? It can create any such device ....

What do you mean?

[christos]

Removed strdup().

[• hselasky]

Try:

pkg install virtual_oss
man virtual_oss

Maybe you find the answer. Else let me know.

--HPS

[christos]

In D32236#727421, @hselasky wrote:

Try:

pkg install virtual_oss
man virtual_oss

Maybe you find the answer. Else let me know.

It can create arbitrary DSP devices but they're "tied" to an actual
/dev/dspX device, right? If so, will this patch break things if the user
passes a VDSP device to mixer(8) for example?

[• hselasky]

In D32236#727716, @christos wrote:

In D32236#727421, @hselasky wrote:

Try:

pkg install virtual_oss
man virtual_oss

Maybe you find the answer. Else let me know.

It can create arbitrary DSP devices but they're "tied" to an actual
/dev/dspX device, right? If so, will this patch break things if the user
passes a VDSP device to mixer(8) for example?

Not neccessarily. It can also be a bluetooth audio device.

--HPS

[• hselasky]

Could you run some tests on your side to confirm that the patches you've made work as expected?

[christos]

Since virtual_oss can create arbitrary virtual devices, this patch might
not work as expected in those cases. It's better that we leave it as is then.
Closing the revision.