Re: [Alsa-user] RME HDSPe MADI under ARM issue with playback

[Axel H. <aho...@gm...>]

Resending without zipped attachment but instead with plain text file.

On Tuesday, June 6, 2017 8:27 PM Takashi Iwai wrote:
> On Mon, 05 Jun 2017 11:49:53 +0200,
> Axel Holzinger wrote:
> >
> > Hi,
> >
> > I'm trying to get a RME HDSPe MADI card to run in an ARM box with Linux
> > 4.1.6. I configured the (vendor specific TI) kernel to support the card
(via
> > hdspm) compiled into the kernel (not as loadable module).
> >
> > The MADI card is detected as a PCI device and the ALSA driver is loaded.
> > Unfortunately playout does NOT work: aplay is reporting an error:
> > ALSA lib pcm_mmap.c:374:(snd_pcm_mmap) mmap failed: No such device
> or
> > address
> 
> Hm, this sounds odd.  But the line doesn't really correspond to the
> latest version of alsa-lib.  Could you try to upgrade to the latest
> version?  Otherwise it's hard to debug.

I installed ALSA with Debian apt-get. How would I update to a newer version?

> > strace:
> > open("/dev/snd/pcmC0D0p", O_RDWR|O_NONBLOCK|O_CLOEXEC) = 4
> > fcntl64(4, F_SETFD, FD_CLOEXEC)         = 0
> > ioctl(4, AGPIOC_ACQUIRE or APM_IOC_STANDBY or
> SNDRV_PCM_IOCTL_INFO,
> > 0xbecdfb64) = 0
> > fcntl64(4, F_GETFL)                     = 0x802 (flags
O_RDWR|O_NONBLOCK)
> > ioctl(4, AGPIOC_INFO or SNDRV_PCM_IOCTL_PVERSION, 0xbecdfacc) = 0
> > ioctl(4, AGPIOC_SETUP or SNDRV_PCM_IOCTL_TTSTAMP, 0xbecdfad4) = 0
> > mmap2(NULL, 4096, PROT_READ, MAP_SHARED, 4, 0x80000000) = -1 ENXIO
> (No such
> > device or address)
> 
> This error is expected and should be OK.  It's an mmap of
> status/control page, and this isn't supported on ARM, thus the kernel
> returns -ENXIO.  alsa-lib then falls back to the normal ioctl instead
> of status/control mmap.

Okay, got it. So is the mmap emulation plugin via asound.conf suggested by
Anders needed then anyhow?

> But the ring-buffer mmap is supported as normal on ARM for MADI
> driver, at least.  MADI provides the SG-buffer that is mappable via
> DMA coherent pages, and it should work on most of archs as is.

Well I found out something more: If I don't give a "--device" parameter to
aplay and the RME card is default, then audio is playing. But I give the "
--device=default:CARD=HDSPMx5c74" then the error is occuring. That doesn't
make sense to me at all. The tests made were with the asound.conf Anders
suggested. Isn't that strange?

> You should have another error from mmap, with a different offset
> value.  That's the real error we need to track down.

I attached the complete strace.

> (And, 4.1.x is pretty old, rather too old for debugging, too...)

Well, I know, but the kernel is a TI based manufacturer kernel for a SoC
(AM5728). I'm not such an expert to update that to current kernel version
unfortunately.

If you don't mind I have another question: If specifying a device
"--device", how would I "send" audio to the "upper" channels/tracks of the
MADI card? If I ommit the "--device" parameter audio is playing on
channels/tracks 1+2. How would I play audio to channels/tracks 33+34 for
example?

Thank you very much for your support!
Axel

> Takashi