STATUS_INSUFFICIENT_RESOURCES

NTDEV
1

Hi all,

Subject: Bus Master Packet Based Scatter Gather DMA (PCI)

Somehow the GetScatterGatherlist function
allways return STATUS_INSUFFICIENT_RESOURCES.

Even if for example:
MapRegsAvailable : 16384 (returned by IoGetDmaAdapter)
MapRegsNeeded : 2048 (Needed for current transfer)
MapRegsGot : 2048 (After check through
ADDRES_AND_SIZE_TO_SPAN_PAGES)

Any ideas what the problem could be?

TIA

2

Assumptions:

  1. You allocated a DAM adapter object (ooops should be DMA)
  2. You provided a DAM execution routine (dam keyboard)
  3. You set up the MDL correctly
  4. You fetched CurrentVA from the MDL
  5. You provided the proper DO
  6. You only have one DAM request on the DAM queue (oh well …)

–
Gary G. Little
Have Computer, Will Travel …
909-698-3191
909-551-2105
http://www.wd-3.com

wrote in message news:xxxxx@ntdev…
>
> Hi all,
>
> Subject: Bus Master Packet Based Scatter Gather DMA (PCI)
>
> Somehow the GetScatterGatherlist function
> allways return STATUS_INSUFFICIENT_RESOURCES.
>
> Even if for example:
> MapRegsAvailable : 16384 (returned by IoGetDmaAdapter)
> MapRegsNeeded : 2048 (Needed for current transfer)
> MapRegsGot : 2048 (After check through
> ADDRES_AND_SIZE_TO_SPAN_PAGES)
>
> Any ideas what the problem could be?
>
> TIA
>
>

3

Thanks for your reply,

I’ve done all of that. I’ve tried
a small request (8k) and that seems
to work just fine.

The question is:
Why does IoGetDAMAdapter (oops DMA ;o))
give me too many map registers?
(MaximumLength is set to 64 MB. IoGetDmaAdapter
seems to provide me with sufficient map register
to even do a 64 Mb transfer)

And another thing:
How does DmaOps->GetScatterGatherList use bus-master
DMA? In other words: How does GetScatterGatherList
provide the hardware abstraction?
(Plx chip in my case. Do I set Plx DMA Chaining
in hardware registers?)

Thanks again!!

4

xxxxx@chess.nl wrote:

And another thing:
How does DmaOps->GetScatterGatherList use bus-master
DMA? In other words: How does GetScatterGatherList
provide the hardware abstraction?
(Plx chip in my case. Do I set Plx DMA Chaining
in hardware registers?)

All it does is construct a scatter/gather list. You have to program your
hardware yourself. There is a sample named SCATGATH in my WDM book that
one of my readers swears worked great when he adapted it for his
hardware.

–
Walter Oney, Consulting and Training
Basic and Advanced Driver Programming Seminars
Now teaming with John Hyde for USB Device Engineering Seminars
Check out our schedule at http://www.oneysoft.com