Re: [Libcdio-devel] OpenBSD vs libcdio vs Audacious

[Edd Barrett]

On Sat, Jan 26, 2019 at 09:51:58PM +0100, Thomas Schmitt wrote:
> Hi,
> 
> > So to answer your question, it's the ioctl itself failing.
> 
> This explains why we see a message.
> It would be better to show errno or strerror() instead of req.retsts.

Yeah, perror() does that already. That's where 'Invalid argument' comes
from. So it's failing with EINVAL.

> Any traces to see in the system logs ?

I was hoping to see something in the dmesg buffer, but alas, nothing.

I printed the scsi command for each request in the hope that we can
compare and spot the problem:

```
cdio_read_audio_sectors
cmd: be 00 00 00 00 00 00 00 25 78 | datalen = 87024
SCIOCCOMMAND: Invalid argument
cdio_read_audio_sectors
cmd: be 00 00 00 00 00 00 00 12 78 | datalen = 42336
cdio_read_audio_sectors
cmd: be 00 00 00 00 12 00 00 12 78 | datalen = 42336
cdio_read_audio_sectors
cmd: be 00 00 00 00 24 00 00 12 78 | datalen = 42336
cdio_read_audio_sectors
cmd: be 00 00 00 00 36 00 00 12 78 | datalen = 42336
cdio_read_audio_sectors
cmd: be 00 00 00 00 48 00 00 12 78 | datalen = 42336
cdio_read_audio_sectors
cmd: be 00 00 00 00 5a 00 00 12 78 | datalen = 42336
cdio_read_audio_sectors
cmd: be 00 00 00 00 6c 00 00 12 78 | datalen = 42336
cdio_read_audio_sectors
cmd: be 00 00 00 00 7e 00 00 12 78 | datalen = 42336
...
```

After consulting the SCSI docs, the first request differs in that it requests
37 bits, whereas the subsequent request 18 bits.

Is there perhaps some constraint on the transfer length? Must it be an even
number, or a power of two, for example?

-- 
Best Regards
Edd Barrett

http://www.theunixzoo.co.uk