[Cbe-oss-dev] [patch 07/16] powerpc and x86_64: Initial port of PCIe endpoint device driver for Axon

[Murali Iyer]

On Thu, 2008-03-13 at 04:57 +0100, Arnd Bergmann wrote:

> > +void axon_initialize_dacs_sysfs(struct axon *axon_priv)
> > +{
> 
> What does this function have to do with sysfs? It seems to just
> set some generic variables per device that happen to also be exported
> through sysfs.
This is request from users.. some might belong to debugfs but several
might have to stay. Team will consider making it easy to read.

> The request size limits seem rather strange to me. User space should not
> assume that you can map anything of this size into the IOMMU. On most
> systems, the IOMMU has a total size of just a few megabytes, shared by
> all devices, and it's certainly not just architecture dependent.
I suspect it is very application specific. we may have to come across
traditional limitations to satisfy the app.
I am not the expert on this.. and need to defer this discussion until
code for mainline is put out..

> I'm not sure I understand what this function is used for, but
> you'll have to audit this when going to a more recent kernel,
> as you can no longer use 'sg + i' for indexing the sg list entry
> with chained scatterlists.
good to know that.. I am sure will hit this issue pretty soon when
we move to the later kernel.