On arm imx6, running mainline 3.19, mounting a SATA CDROM fails aprox 
1/20 times with this error....

root@freescale /tmp$ mount /dev/sr0 test/
UDF-fs: warning (device sr0): udf_fill_super: No partition found (2)
mount: mounting /dev/sr0 on test/ failed: Invalid argument

I've tried several disks and dvd drivers.  They all experience this 
issue.  The same disks mount 100% of the time on an x86 machine.  Once 
mounted, I can read data without issue.  Also tried a HDD on the same 
SATA link, no issue.

Sometimes the kernel will dump out the attached backtrace on the mount 
command.

-- 
Jonathan Bagg
Embedded Systems Developer
NAD Electronics | Lenbrook Industries Limited
633 Granite Court, Pickering, Ontario, Canada L1W 3K1 | 905-831-0799 ext 4478 | http://www.nadelectronics.com