In the Linux kernel, the following vulnerability has been resolved:
ata: pata_via: Force PIO for ATAPI devices on VT6415/VT6330
The controller has a hardware bug that can hard hang the system when doing ATAPI DMAs without any trace of what happened. Depending on the device attached, it can also prevent the system from booting.
In this case, the system hangs when reading the ATIP from optical media with cdrecord -vvv -atip on an _NEC DVD_RW ND-4571A 1-01 and an Optiarc DVD RW AD-7200A 1.06 attached to an ASRock 990FX Extreme 4, running at UDMA/33.
The issue can be reproduced by running the same command with a cygwin build of cdrecord on WinXP, although it requires more attempts to cause it. The hang in that case is also resolved by forcing PIO. It doesn't appear that VIA has produced any drivers for that OS, thus no known workaround exists.
HDDs attached to the controller do not suffer from any DMA issues.