Re: 2.6.18-rc1-mm1

Jeff Garzik
2006-07-09T16:29:27Z

Alan Cox wrote:
> The old drivers/ide code uses much longer delays than the spec for some
> ATAPI commands, and it looks as if there is a good reason for doing
> so ...

FWIW, the code that ATADRVR (http://www.ata-atapi.com/) uses to issue
commands does something like

write Command register to start command
if (device == ATAPI) # i.e. not ATA
delay(150 msec)
pound Status / AltStatus, kick DMA engine, whatever else

ATADRVR is open code (for an MS-DOS-level driver), and really worth a
read. Between ATADRVR and drivers/ide, you get a pretty good idea about
what __field experience__ has shown is needed for ATAPI devices.

Jeff