[ELDK] Problem accessing 16MB PCI memory mapped to user space

Wolfgang Denk wd at denx.de
Thu Jul 1 09:56:40 CEST 2010

Dear Kris Modrak,

In message <BAY145-w2B56FCBCDBF441C6C7135D2CC0 at phx.gbl> you wrote:
> I am developing a driver for a custom PCIe device that makes a 16MB
> PCI memory space available to user space via mmap.
> From user space I can access only some of the mapped memory, from 8MB
> onwards. Reads to the memory 0-0x7FFFFF never return.
> However, from kernel space I am able to access the memory range
> 0-0x7FFFFF, so it doesn't seem to be an issue with my hardware.
> I connected my PCIe device to a desktop PC running ubuntu, with the
> same driver, same PCIe device and same user space test applications I
> was able to access the whole of the PCI memory from user space.
> I'm using ELDK 4.2, kernel on a P2020RDB target.

We don't know your hardware, we don;t know your kenrel port to your
hardware, we don't know your custom PCIe device, we don't know your
driver for it, we don't know your changes to the device tree to
describe this hardware, we don;t see your kernel's log messages, we
don't see your system's output of the "lspci" command with suitable
options - we don't know nothing.

How do you expect us to help without any of the relevant information?

Also, your question has nothing to do with the ELDK, so you are off
topic on this list. I suggest you repost (with more information) on
the PPC mailing list.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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