Re: Problem accessing Sandisk CompactFlash Cards (Connected to the IDE bus)

[Marc Strämke]

> Tracing back through the code it looks to me like we get the ATA disk 
> print in the event that this test in do_identify:
> /*
>  * Check for an ATAPI device
>  */
>  if (cmd == WIN_PIDENTIFY) {
>
> that would explain why the drive_is_flashcard test is getting skipped, 
> why setting removable is making no difference, and why your card is 
> being identified as an ATA device.  It looks as though the WIN_PIDENTIFY 
> command is sent down to this routine from ide_probe_for_drive in this 
> snip of code:
>
> /* if !(success||timed-out) */
>                 if (do_probe(drive, WIN_IDENTIFY) >= 2) {
>                         /* look for ATAPI device */
>                         (void) do_probe(drive, WIN_PIDENTIFY);
>                 }
Both Cards, the old and the new on dont get to the ATAPI probing (which 
seems correct to me, or is compactflash an ATAPI device???)


> So it would seem that WIN_PIDENTIFY is issued only if a WIN_IDENTIFY 
> command fails with an rc greater than 2.  I would suggest instrumenting 
WIN_IDENTIFY returns a rc of 0 (for success) with both the old and the 
new card. Still the old ones gets detected as CFA!


One thing i did notice when tracing these functions, is that the new 
card returns 0x44a in drive->id->config, while the old one returns 
0x848a, according to the manual from 
SanDisk(http://www.sandisk.com/pdf/industrial/ProdManualIndustrialGradeATAv2.6.pdf) 
Should only be returned in memory mapped(cardbus/pc-card) mode, and not 
in True IDE mode, which the card is appearently running, otherwise the 
bios couldnt not boot from it, nor would the electrical interface be 
compatible (if i get the manual right). That is imo why hdparm -I doesnt 
detect the card as beein removable and Compactflash too, i looked as the 
sourcode of hdparm, and it seems to read the ATA configuration registers 
trough a proc file, and interpret it directly (without intervention of 
the kernel).
So the data the does return indeed marks it as an ATA harddisk, and not 
as a compactflash card, the real question then is why doesnt it work as 
a harddisk, which according to the specifications it should? Iam not 
really experienced in the ide stuff, so iam not sure what the 
CompactFlash detection in linux changes in behaviour.
I can get the kernel to report it as a "CFA DISK Drive" in dmesg by 
forcing the flags i mentioned before, but the error is exactly the same.

Thx for your help,
Marc

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