CONFIG_IDEDMA_AUTO & 2.4.32 & hdparm -d1

["Wijnand Rietman" <wijnand.rietman@gmail.com>]

Hello,

I am running Linux on a PC104 board from a compact flash card. Because
the physical DMA lines are missing on some of the compact flash
carrier cards, I would like to be able to boot with DMA disabled and
to enable DMA in a later stage if desired (and supported by hardware).

The problem is that when I set CONFIG_IDEDMA_AUTO to FALSE, I cannot
enable DMA anymore with hdparm, not even with hardware that supports
DMA. If I set CONFIG_IDEDMA_AUTO to TRUE, I can use hdparm to disable
and enable DMA (but of course I get long timeouts with the carrier
cards that do not have the physical DMA lines).

Q1: Is this how the CONFIG_IDEDMA_AUTO setting is supposed to work in
combination with hdparm?
Q2: Is there a way to boot with DMA disabled and to enable it later on
once the system is up and running?

Kernel: 2.4.32
Chipset: CS5530

Any help is highly appreciated!

Regards,
Whinyan
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