On Sunday 28 of March 2004 00:40, Jeff Garzik wrote:

Jeff Garzik wrote:

quoted

That's the main limitation on request size right now...  libata limits
S/G table entries to 128[1], so a perfectly aligned, fully merged

    ...

[1] because even though the block layer properly splits on segment
boundaries, pci_map_sg() may violate those boundaries (James B and
others are working on fixing this).  So...  for right now the driver
must check the s/g entry boundaries after DMA mapping, and split them
(again) if necessary.  IDE does this in ide_build_dmatable().

You are right but small clarification is needed: code in ide_build_dmatable()
predates segment boundary support in block layer (IDE never relied on it).