Re: Fwd: No audio in HW Compressed MPEG2 container on HVR-1300

[lawrence rust <lawrence@softsystem.co.uk>]

On Fri, 2010-08-06 at 11:49 +1200, Shane Harrison wrote:
[snip]
> Well still no luck this end.  Have done the following:
> 1) Swapped boards - no change
> 2) Applied the patch - no change (we were detecting the WM8775 OK
> anyway and the other changes were either non HVR-1300 or we had
> already tried them so probably not too surprising
> 3) Made sure I2SINPUT is enabled - no change
> 
> So still have the following strange observations:
> 1) Repeatedly swapping between inputs eventually gives us audio
> 2) Once fixed it survives a warm reboot but not power cycle

Because of the the warm boot survival I'm tempted to think that this is
a cx23416 firmware problem.

I don't have any experience with cx23416 programming but from looking at
cx88-blackbird.c it appears that the firmware is only loaded from the
function blackbird_initialize_codec() if the chip doesn't respond to a
'ping' command.  blackbird_initialize_codec() is called during probing,
during the first open and whenever the tuner frequency is changed - i.e.
when inputs are changed.  I would be tempted to set this module's debug
parameter and see if there's a coincidence of resetting/reloading the
firmware and the audio path being enabled.

> 3) Putting a scope on the I2S line out of the CX2388x shows noise when
> TV input selected and no noise for Composite (unless inject a tone).

This confirms that the cx2388x is setup OK

> However MPEG-2 audio always contains hiss or hiss plus injected tone.

This tells me that the cx23416 is not configured right.

> So looks like two issues to me.  I'll try and modify the driver so
> that when switching inputs we only config the WM8775 or the CX2388x or
> the MPEG encoder and see if I can determine which item has the
> configuration issue.

Seems like a good idea, but I would put money on the cx23416.

I would recommend looking at the debug output from cx88-blackbird and if
there's anything unusual then temporarily disable the ping test in
blackbird_initialize_codec() and always reset and re-load the firmware.
If this helps then maybe add some delays around the reset for a long
term fix.

-- Lawrence Rust