Although I submit these patches as the previous reply suggestion, I
am stilling wondering the IOMMU with USB controller. I think the most
of USB controller didn't need to create entities in IOMMU to support
scatterlist. Once the hcd supports that(sg_tablesize > 0), it could
support infinite scatter pages?

Randy Li (2):
  USB: dma: remove unused function prototype
  docs: driver-api: usb: update dma info

 Documentation/driver-api/usb/dma.rst | 48 +++++++---------------------
 include/linux/usb.h                  | 16 ----------
 2 files changed, 11 insertions(+), 53 deletions(-)

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2.41.0