Re: Testing IDE-TCQ and Taskfile - doesn't work nicely:)

From: Jeff Garzik (jgarzik@pobox.com)
Date: Tue Jun 24 2003 - 09:28:41 EST


Bartlomiej Zolnierkiewicz wrote:
> TCQ shouldn't be enabled on hdc, you have two drives on second ide
> channel and current TCQ driver design allows only one drive per channel,
> so proper fix is to not enable TCQ :-).

IMO the best rule is "enable TCQ if and only if 100% of the channel
supports TCQ".

So, two drives on the same channel can do TCQ, if and only if they both
support TCQ. That's a big benefit of bus release, after all,
simultaneously servicing multiple drives. The device-select and service
interrupt semantics are annoying but doable.

        Jeff

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Mon Jun 30 2003 - 22:00:16 EST