Re: [PATCH] libata: add support for READ/WRITE LONG

[Mark Lord <liml@rtr.ca>]

Sergei Shtylyov wrote:
>..
>    Well, those ATA specs have always been quite messy: for example, 
> polling protocol had an unnoticed race for years (device was allowed to 
> clear BSY before asserting INTRQ, so there was no guarantee that the 
> host's reading of the status reg. will actually clear drive's interrupt)...

Hey.. a chap after my own heart!  Been there, done that!

> NOTE 31 - Some ATA-1 devices are not capable of delivering the 8 bit ECC 
> immediately after the word sector data. BIOS and driver developers 
> should use PIO mode 0 for 8 bit ECC accesses.

Exactly.  But we're not really interested so much in the rare ATA1 drive
that fails (the ATA1 Conner unit I have here works fine with this patch).

The idea here is to give us a way to inject errors into (more or less)
current drives (ata6/7 vintages) so we can see what happens when FPDMA
on a SATA drive hits a bad sector, etc..

For which it seems to work rather well.

Cheers