Hi Andy, On Thu, Jan 28, 2010 at 9:24 PM, Andy Walls <awalls@xxxxxxxxx> wrote: > Devin, > > I found interesting system interactions. On my dual core x86_64 Fedora > 12 machine loading an HVR-1600 cold (no firmware has been loaded yet), > the pulseaudio daemon opens up a CX23418 ALSA node almost immediately > after it appears and has these effects: > > 1. Pulseaudio tries to perform some sort of op that starts a capture on > the PCM stream before the APU and CPU firmware has finished loading. > This results in error messages in the log and probably an undesirable > driver state, if there was never any firmware loaded prior - such as at > power up. I'm a little surprised by that, since the cx18-alsa module is only initialized after the rest of the cx18 driver is loaded. > 2. Pulseaudio grabs the ALSA control node for the CX23418 and won't let > go. If I kill the Pulseaudio process that has the node open, it just > respawns and grabs the control node again. This prevents unloading the > cx18-alsa and cx18 module. As far as I know, this is one of those dumb Pulseaudio things. Doesn't it do this with all PCI cards that provide ALSA? > 3. If Pulseaudio also keeps the PCM analog stream going, then TV image > settings are fixed to the values at the time Pulseaudio started the > stream. I don't think it does, but I'm not sure yet. I know that Pulseaudio binds to the device, but as far as I know it does not actually open the PCM device for streaming. > My off the cuff ideas for fixes are: > > 1. Integrate cx18-alsa functions into the driver and no longer have it > as a module, to better coordinate firmware loading with the ALSA nodes. > (The modular architecture appears to have been a bad choice on my part.) I'm not against merging the two into a single module, although it's not clear to me that it will help with the issues you are seeing. > 2. Add a module option to disable setting up the cx18-alsa device nodes. I can see some value in such an option in general for debugging purposes, although I don't think it provides a whole lot of value for regular users who would not normally have it enabled. > > I'll try to work on these this Friday and Saturday. I will be out of town this weekend, but if you send me email I will try to respond as promptly as possible. Devin -- Devin J. Heitmueller - Kernel Labs http://www.kernellabs.com -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
