Using two distinct DMA zones turned out to be problematic. Here's an
attempt go back to a saner default.

I tested this on both a RPi4 and QEMU.

---

Nicolas Saenz Julienne (4):
  of/fdt: Update zone_dma_bits when running in bcm2711
  dma-direct: Turn zone_dma_bits default value into a define
  arm64: Default to 32-bit ZONE_DMA
  mm: Update DMA zones description with arm64 newer behavior

 arch/arm64/mm/init.c       | 12 ++++++++----
 drivers/of/fdt.c           | 10 ++++++++++
 include/linux/dma-direct.h |  1 +
 include/linux/mmzone.h     |  5 +++--
 kernel/dma/direct.c        |  2 +-
 5 files changed, 23 insertions(+), 7 deletions(-)

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2.28.0