[ros-dev] Re: [ros-svn] [hbirr] 17665: - Copy the map registers to
the buffer only, if they are used (in IoFlushAdapterBuffers).
xnavara at volny.cz
Mon Sep 5 22:43:45 CEST 2005
hbirr at svn.reactos.com wrote:
>- Copy the map registers to the buffer only, if they are used (in IoFlushAdapterBuffers).
>- Do not use the byte offset into the page from a given buffer if the map registers are used,
> because the caller didn't request for one additional register in the call to IoAllocateAdapterChannel
> and it will not work for a 64k buffer.
Sorry, but these changes are wrong. I won't argue that there isn't bug,
but you're just workarounding it.
- At first, the UseMapRegisters variable you added to MAP_REGISTER_ENTRY
structure isn't needed. IoFlushAdapterBuffers can determine the
information itself and the case was clearly marked as UNIMPLEMENTED and
- The byte offset is added for a reason. I know the stuff that it is
supposed to solve is broken atm, but the rationale is that there can be
more IoMapTransfer calls and together with MAP_REGISTER_ENTRY->Counter
you can setup more transfers... It's explained in
I certainly welcome any help and review of the DMA code and I'll try to
add comments where appropriate, but I would like to discuss these
changes first on the Mailing List / IRC / mail since this piece of code
is pretty complex and any changes are prone to break some feature...
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