Re: Trouble using some (fast) compact flash as ide device on an embedded system

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Friday 02 March 2007, Pavel Machek wrote:
> Hi!
> 
> > As I reported in bug 8036 in bugzilla.kernel.org,
> > 
> > Hardware Environment:
> > 
> >  - Use a compact flash SanDisk SDCFB-128 Firmware revision HDX 2.15
> >    (we used other compact flashes with the same hw ad sw for years
> >     with  no trouble)
> > 
> > It happens on both etx boards:
> >  - VIA SOM-ETX (4475)
> >  - Gene-4312
> > 
> > Doing the command
> > sfdisk -R /dev/hdc
> > 
> > gives:
> > 
> >  * * *
> > ide1: start_request: current=0xc6ebe754 (rq->sect=0,block 0)
> > hdc: status error: status=0x58 { DriveReady SeekComplete DataRequest }
> > ide: failed opcode was: unknown
> > hdc: drive not ready for command
> > ide1: start_request: current=0xc6ebe754 (rq->sect=0,block 0)
> > hdc: do_special: 0x02
> > hdc: do_special: recalibrate
> > ide1: start_request: current=0xc6ebe754 (rq->sect=0,block 0)
> > hdc: reading: block=0 sectors=8, buffer = 0xc6cd40000
> > ide1: end_request: current=0xc6ebe754
> >  * * *
> > 
> > the 'bad bit' in status error is DataRequest
> > 
> > 
> > 
> > doing
> > sfdisk -l /dev/hdc
> > 
> > gives:
> > 
> >  * * *
> > ide1: start_request: current=0xc6ebecd4 (rq->sect=0,block 0)
> > hdc: reading: block=0, sectors=32, buffer=0xc6f37000
> > hdc: lost interrupt
> > hdc: lost interrupt [and so on several times]
> >  * * *
> > 
> > I have no knowledge of the internals of the linux kernel, but I'm a
> > programmer and have both hardware and time to spend on solving this issue.
> 
> Debug it, then :-). Try limiting its speed with hdparm to see if it
> helps.

I would suggest trying booting with "ide=nodma" first.

Should help if this is CF adapter without DMA support with DMA capable CF.
[ Hmm, this should be in the documentation somewhere but actually isn't. ]

Thanks,
Bart