Messages in this thread |  | | Date | Wed, 7 May 2003 19:50:33 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] 2.5 ide 48-bit usage |
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On Wed, May 07 2003, Linus Torvalds wrote: > > On Wed, 7 May 2003, Jens Axboe wrote: > > > > > > And testing. In particular, you might want to test whether a device > > > properly supports 48-bit addressing, either from the kernel or from user > > > programs. > > > > For that, a forced 48-bit hwif->addressing inherited by drives will > > suffice. And I agree, we should have that. > > No no no. > > You definitely do NOT want to set "hwif->addressing" to 1 before you've > tested whether it even _works_.
Well duh, of course not. Whether a given request is executed in 48-bit or not is a check that _includes_ drive capabilities too of course.
> Imagine something like "hdparm" - other things are already in progress, > the system is up, and IDE commands are potentially executing concurrently. > What something like that wants to do is to send one request out to check > whether 48-bit addressing works, but it absolutely does NOT want to set > some interface-global flag that affects other commands.
Then it just puts a taskfile request on the request queue and lets it reach the drive, nicely syncronized with the other requests. There's no need to toggle any special bits for that.
> Only after it has verified that 48-bit addressing does work should it set > the global flag.
Sounds fine.
-- Jens Axboe
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