Re: Awful long timeouts for flash-file-system

From: Robert Hancock
Date: Tue Mar 15 2005 - 00:24:07 EST

linux-os wrote:

Hello IDE experts.

I am trying to use a SanDisk SDCFB-256, CFA DISK drive. This
is supposed to emulate an IDE drive and does (sort of). However,
upon boot, the boot-code keeps trying and trying and trying to
do SOMETHING that aparently isn't even necessary because the
virtual disk is accessible and can be written/read and I can
even boot from it.

hdb: max request size: 128KiB
hdb: 501760 sectors (256 MB) w/1KiB Cache, CHS=980/16/32, DMA
hdb: cache flushes not supported
hdb:<4>hdb: dma_timer_expiry: dma status == 0x61

I'm assuming you're using a CF-to-IDE adapter to hook up the card. Most likely your CompactFlash card is indicating that it supports DMA and the kernel is trying to use it. However, many CF-to-IDE adapters don't hook up the DMA control lines properly so the requests all time out until the kernel gives up using DMA.

We use some Mesa Electronics CF-IDE adapters at work - some of the newer ones have some jumpers with positions NOR and DMA, DMA works if the jumpers are set to the DMA position. I don't think we've tried using any DMA-supporting CF cards on the older ones without these jumpers.

If the adapter you're using doesn't do DMA, I believe that if you use options like hdb=nodma or ide1=nodma, etc. that will get the kernel to not try and use it.

Robert Hancock Saskatoon, SK, Canada
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