RE: floppy drive works under XP, W2K Dos but not NT4(SP6a)

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From: CKNC (CKNC_at_discussions.microsoft.com)
Date: 11/12/04 

Date: Fri, 12 Nov 2004 12:00:01 -0800

I think I found the problem. It is due the the 8bit DMA engine can only use
the memory below 1M as the destination. Somehow, in W2k and XP, the os knows
to use the low address to setup the floppy DMA, but NT4.0 doesn't. Does
anyone know if there is any init setting to tell the OS to use the memory
below 1M to setup the floppy DMA.

Thanks.

"CKNC" wrote:

> I have a board with intel 440 MX chip set on it and the floppy drive works
> fine under XP,W2K and DOS. However it does not work under NT4, SP6a. The
> message shows "the volume does not contain a recognized file system .......
> volume is corrupt".
>
> I can use the NT4 DDK floppy source code to recreate the problem. After
> trace through the code, the finding is that after issue the floppy read
> command, the DMA ch2 will handshake the data out of the Xbus floppy
> controller (verified by tag the xbus signal through logic analyzer), DMA
> engine shows it finish the transfer count, no error from the floppy
> controller either, however the system memory destination of the DMA area is
> not updated.
>
> I had put a breakpoint after the DMA setup function "IoMapTransfer". and
> retrieve the current DMA channel setting to know what is the physical memory
> area it DMA to and monitor the area before and after the floppy read command.
> The data in the area is not changed. If we fake the data by puting correct
> floppy data in the DMA memory region, the driver is happy and continues ask
> the next sector. We thought this may be a cache issue, however by turning off
> the cache, the situation still happen. I was trying to know how
> "IoMapTransfer" function setup the DMA, however, this is a kernel call and no
> source is provided.
>
> I am not assuming this is a hardware issue, due to the fact that XP, W2K and
> DOS all work fine. The floppy controller is on SMSC FDC37B727 superIO chip.
> I am wondering has any one ever see issue like this about the DMA? Any
> comment are welcomed.

Relevant Pages

  • floppy drive works under XP, W2K Dos but not NT4(SP6a)
    ... I have a board with intel 440 MX chip set on it and the floppy drive works ... I can use the NT4 DDK floppy source code to recreate the problem. ... controller, DMA ... DOS all work fine. ...
    (microsoft.public.development.device.drivers)
  • Re: [Intel IOMMU 10/10] Iommu floppy workaround
    ... floppy device so that the floppy device which does not use ... DMA api's will continue to work. ... Once the floppy driver starts using DMA api's this config option ... +static inline void iommu_prepare_isa ...
    (Linux-Kernel)
  • floppy drive works under XP, W2K Dos but not NT4(SP6a)
    ... I have a board with intel 440 MX chip set on it and the floppy drive works ... I can use the NT4 DDK floppy source code to recreate the problem. ... controller, DMA ... retrieve the current DMA channel setting to know what is the physical memory ...
    (microsoft.public.development.device.drivers)
  • Re: bug in kernel 2.6.21-rc1-git1: conventional floppy drive cannot be mounted without hangi
    ... I know nothing about floppy, but I guess the reason is floppy_disable_hlt. ... But it used to be that the native DMA by ... data if the CPU was halted while the DMA took place. ... The floppy is still pretty much the only user of native motherboard (aka ...
    (Linux-Kernel)
  • [PATCH] spelling fixes: arch/arm/
    ... copy data to/from buffers located outside the DMA region. ... the remainder of memory is at the top and the DMA memory ... Peers on the PCI bus running ... - * devices are controlles by different NPUs on the same bus, ...
    (Linux-Kernel)