Re: ICH Intel PATA short cable override...

From: Jeff Garzik
Date: Sun Sep 16 2007 - 03:58:25 EST


Mark Lord wrote:
Jeff Garzik wrote:
Mark Lord wrote:
Ditto for selecting transfer modes.


Waiting on one thing AFAICS:

ability to drain/idle all ports +
issue a command on one port +
resume normal parallel port operation

SET FEATURES - XFER MODE is special in that it requires all sorts of additional controller handling and careful cross-port synchronization.

Absolutely.

Also note that I'm *not* advocating HDIO_SET_PIO_MODE (and kin) here,
but rather perhaps a sysfs option per-drive. It is needed, especially for
custom/embedded systems, and I suppose we will get there eventually. :)

(did I reply to this already? I forget)

We don't need any sysfs options. Just normal SG_IO sending a SET FEATURES - XFER MODE command to the desired device.

Currently, that [sub-]command is intentionally filtered out because of the problems that would ensue.

Once the above EH mods are in place, we simply remove that filter, and The Right Thing(tm) happens when you submit an ATA command via normal methods. No need for new sysfs hooks or new ioctls or anything.

Jeff



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