Re: [PATCH 13/19] thunderbolt: Add QUIRK_NO_DMA_PORT

[Mika Westerberg]

Hi,

On Sun, Aug 30, 2026 at 10:19:31PM +0200, Sven Peter wrote:
> Apple Silicon machines load and update the host router firmware with a
> separate, proprietary mechanism and have no DMA port. Add a quirk to
> skip its initialization.

DMA port is Intel Thunderbolt 1-3 thing and not expected to found on USB4
routers. The current code should not even be trying to find it, if it does
then that's a bug that should be fixed.

USB4 router firmware upgrades use the standard operations and if those are
not supported then we just don't expose the corresponding NVMem nodes.