linux-ide.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jeff Garzik <jeff@garzik.org>
To: Tejun Heo <tj@kernel.org>
Cc: IDE/ATA development list <linux-ide@vger.kernel.org>,
	"Zhao, Richard" <Richard.Zhao@amd.com>,
	shane.huang@amd.com
Subject: Re: [PATCH RFC] ahci: implement handoff quirk
Date: Sat, 11 Apr 2009 12:54:51 -0400	[thread overview]
Message-ID: <49E0CB5B.3070807@garzik.org> (raw)
In-Reply-To: <485882FE.1060409@kernel.org>

Tejun Heo wrote:
> ahci 1.2 has an exciting! new feature called BIOS/OS handoff which
> basically is there to allow BIOS to keep tinkering with the controller
> even after OS starts executing.  I have no idea what this is useful
> for but it's there and we need to do it.
> 
> This patch implements the handoff as FIXUP_HEADER as the controller
> needs to be claimed before the OS changes any configuration including
> IRQ routing.
> 
> I'm yet to see any controller which actually requires this, so it's
> not for inclusion yet.  Maybe keep this in a separate branch?
> 
> RFC, DON'T COMMIT

We probably need to do this...

it's not a controller requirement but a BIOS one, so in theory even an 
existing, deployed AHCI 1.2 platform could suddenly require BIOS/OS 
handoff, if a BIOS update suddenly starts doing new and weird stuff in SMI.

Note that we need to do BIOS/OS handoff upon resume as well as at boot time.

	Jeff




  reply	other threads:[~2009-04-11 16:54 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-18  3:37 [PATCH RFC] ahci: implement handoff quirk Tejun Heo
2009-04-11 16:54 ` Jeff Garzik [this message]
2009-04-11 17:51   ` Tejun Heo
2009-04-11 18:02     ` Jeff Garzik
2009-04-14  9:16       ` Tejun Heo
2009-04-14  9:41         ` Jeff Garzik
2009-04-15  1:54           ` Huang, Shane
2009-12-17  6:34 ` Jeff Garzik
2009-12-18  3:54   ` Robert Hancock

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=49E0CB5B.3070807@garzik.org \
    --to=jeff@garzik.org \
    --cc=Richard.Zhao@amd.com \
    --cc=linux-ide@vger.kernel.org \
    --cc=shane.huang@amd.com \
    --cc=tj@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).