DMA-API: cacheline tracking ENOMEM, dma-debug disabled due to nouveau ?

[Corentin Labbe]

Hello

Since lot of release (at least since 4.19), I hit the following error message:
DMA-API: cacheline tracking ENOMEM, dma-debug disabled

After hitting that, I try to check who is creating so many DMA mapping and see:
cat /sys/kernel/debug/dma-api/dump | cut -d' ' -f2 | sort | uniq -c
      6 ahci
    257 e1000e
      6 ehci-pci
   5891 nouveau
     24 uhci_hcd

Does nouveau having this high number of DMA mapping is normal ?

Regards