On Thu, Aug 25, 2022 at 06:50:25PM +0000, Will McVicker wrote: > Since not all devices require a 32-bit MSI address, add support to the > PCIe host driver to allow setting the DMA mask to 64-bits if the 32-bit > allocation fails. This allows kernels to disable ZONE_DMA32 and bounce > buffering (swiotlb) without risking not being able to get a 32-bit address > during DMA allocation. Umm. You can't just disable ZONE_DMA32. Linux absolutely requires a 32-bit dma mask to work, it is in fact the implicit default.
