Re: [PATCH] IDE TCQ #4

Jens Axboe
2002-04-15T16:18:31Z

On Mon, Apr 15 2002, Aaron Tiensivu wrote:
> Simple question but hopefully it has a simple answer.. is there a command
> you can issue or flag you can look for from the output of hdparm to tell if
> your hard drive is capable of TCQ before installing the patch? I have a few
> IBM drives that I'm sure have TCQ abilities but I don't trust them as far as
> I can throw them (being Hungarian and cursed) but I'd like to give TCQ a
> whirl on my WD 120GB drives that should work OK, if they support TCQ..
>
> Sorry if it's already been asked.. :)

It has not been asked :-)

You can run a IDENTIFY_DEVICE from user space with the task ioctls and
look at word 83 -- bit 1 and 14 must be set for TCQ to be supported. If
you give me the model identifier from the IBM drive, I can tell you if
it has tcq or not...

I'll write a small util to detect this tomorrow and send it to you + the
list.

I thought only the IBM's had TCQ, but I got one report today indicating
that some WD do too.

--
Jens Axboe