Dear Tim Roberts,
??? May be you did think that I must configure the device
for some purpose and it operates its function.Then, we can say
that device works OK.
??? However, as requirement from my customer, my driver
can access read/write to IO port. That’s all.
So , I tested my driver with VGA about I/O access which
allow me to access read/write.
Anyway, Thank you very much for your kindness in
helping answer my silly questions !
Best Regards
HanNguyen
Nguyen Nhat Han
MobiPhone : 0906.739.923
C?ng ty : Cty TNHH Thiet ke Renesas
— On Sat, 7/30/11, Tim Roberts wrote:
From: Tim Roberts
Subject: Re: [ntdev] [About IO access in PCIe]
To: “Windows System Software Devs Interest List”
Date: Saturday, July 30, 2011, 12:20 AM
Nhat Han wrote:
>? ? ???
>? ???When I used “MmmapIOSpace” for IO ,example : 0xE800. It didn’t map
> my IO space to memory but it did map the
> physical memory 0x0000E800 to memory space. And when I use freeware to
> confirm I did check the memory
> at 0xE800 but not the IO area. So , it makes me think that
> MmmapIOSpace can work.
>
Of course, it can, but not for I/O ports.
>? ? ? Actually, VGA card IO space can be accessed only in some range
> (example : from 0xE820 to 0xE870) . And when I used
> “WRITE_PORT_…” at 0xE800 . It doesn’t take effect. Then, I make me
> think that my implementation doesn’t work with “WRITE_PORT_…”
>
Your implementation of what?? How would you device “work” if you’re
talking to a device you don’t understand?
> Since, my PC hang up when I used “WRITE_PORT_BUFFER_UCHAR” at address
> 0xDC21 with size = 1B? ( IO access) . The same problem for
> "WRITE_REGISTER_BUFFER_UCHAR at address b980d009 with size = 1B .(
> memory access )
>
What did you expect that to do?? Do you have any idea what the registers
at those locations do?? Are you sure that’s not the “self-destruct
trigger”?? If you’re writing to your graphics card, you might actually
be writing to the memory tuning registers, and thereby kill your screen.
I’m not sure how to get this point across.? You cannot just write to
arbitrary registers in devices you don’t control.? End of story.? Stop
asking questions about why it doesn’t “work”, because it’s NEVER going
to work.
–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.
—
NTDEV is sponsored by OSR
For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars
To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer