[mythtv-users] Lost sound on live TV after upgrades?

[Nick]

On 06/09/06, David Rees <drees76 at gmail.com> wrote:
> On 9/6/06, Nick <knowledgejunkie at gmail.com> wrote:
> > On 06/09/06, David Rees <drees76 at gmail.com> wrote:
> > > I recently lost sound in mythfrontend after a reboot and I found that
> > > /dev/dsp /dev/mixer, etc aren't read/writable by mythtv anymore.
> > > Trying to figure out why.
> >
> > New default udev rule? I've created my own so that any future udev
> > updates do not alter my device ownership or permissions.
>
> Must be something like that, but the default rules haven't changed recently.

Just remembered something else - consule security permissions will
also affect the permissions on many devices when you log in -
/etc/security/console.perms.d/50-default.perms - like udev rules this
can be edited or you can create another with the rules you want to use
for each/any class.

For sound/v4l/dvb and lirc I use (replacing class with the actual class name)

<console>  0600 <class>      0660 root.htpc

In udev, I use (called 10-oss.rules)

KERNEL=="dsp*",                 GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="audio*",               GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="midi*",                GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="mixer*",               GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="sequencer*",           GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="sound/*",              GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="snd/*",                GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="beep",                 GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="admm*",                GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="adsp*",                GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="aload*",               GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="amidi*",               GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="dmfm*",                GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="dmmidi*",              GROUP="htpc", MODE="0660", OPTIONS="last_rule"
KERNEL=="sndstat",              GROUP="htpc", MODE="0660", OPTIONS="last_rule"

This works for me - I created it a while back and haven't looked to
see if it's the most efficient way of doing it - it likely isn't. The
fun and games I had was trying to work out why my udev rules were not
working - I did some digging and found that console.perms was altering
device ownership/permissions thus obfuscating udev's effects whilst I
was logged in. udev logging was also broken so I couldn't easily see
how the devices were being created initially.

Nick

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