LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Jeff Garzik <jeff@garzik.org>
To: Tejun Heo <htejun@gmail.com>
Cc: Linux IDE mailing list <linux-ide@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: devres and requesting resources
Date: Thu, 28 Feb 2008 19:36:34 -0500	[thread overview]
Message-ID: <47C75392.3020606@garzik.org> (raw)

Something I just noticed, which I missed during the initial devres review...

The vast majority of my ATA drivers originally called 
pci_request_regions(), to reserve all regions attached to a device.

In converting to pcim_iomap_regions(), we no longer reserve /all/ 
regions, only the ones requested.

This is actually a bug:  it was intentional to call 
pci_request_regions(), because that ensures that no other software will 
use our resources -- even if we are not actively using the resource in 
question.

Or IOW, I wanted to ensure that there would be no device sharing... 
which this devres conversion accidentally enabled.

The simple fix is obviously to replace pci_request_region() call with 
pci_request_regions() in lib/devres.c, but I wonder if that will break 
any existing driver?

	Jeff



             reply	other threads:[~2008-02-29  0:36 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-29  0:36 Jeff Garzik [this message]
2008-02-29 11:26 ` Alan Cox
2008-02-29 12:11   ` Jeff Garzik
2008-02-29 12:28     ` Tejun Heo
2008-02-29 14:01       ` Alan Cox
2008-02-29 14:17         ` Tejun Heo
2008-02-29 19:25           ` Jeff Garzik
2008-02-29 17:04         ` Bartlomiej Zolnierkiewicz
2008-02-29 17:04           ` Alan Cox
2008-02-29 13:55     ` Alan Cox

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=47C75392.3020606@garzik.org \
    --to=jeff@garzik.org \
    --cc=htejun@gmail.com \
    --cc=linux-ide@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --subject='Re: devres and requesting resources' \
    /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

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).