From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Grant Likely <grant.likely@secretlab.ca>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <greg@kroah.com>,
linux-kernel@vger.kernel.org,
Manjunath GKondaiah <manjunath.gkondaiah@linaro.org>,
Dilan Lee <dilee@nvidia.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH v3] drivercore: Add driver probe deferral mechanism
Date: Mon, 26 Sep 2011 16:12:10 +0100 [thread overview]
Message-ID: <20110926151210.GO22455@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20110926141643.GK2946@opensource.wolfsonmicro.com>
On Mon, Sep 26, 2011 at 03:16:43PM +0100, Mark Brown wrote:
> On Thu, Sep 22, 2011 at 12:51:23PM -0600, Grant Likely wrote:
> > Allow drivers to report at probe time that they cannot get all the resources
> > required by the device, and should be retried at a later time.
>
> > This should completely solve the problem of getting devices
> > initialized in the right order. Right now this is mostly handled by
> > mucking about with initcall ordering which is a complete hack, and
> > doesn't even remotely handle the case where device drivers are in
> > modules. This approach completely sidesteps the issues by allowing
> > driver registration to occur in any order, and any driver can request
> > to be retried after a few more other drivers get probed.
>
> So, one issue I did think of the other day while putting some support in
> the regulator core for using this: what happens with devices which can
> optionally use a resource but don't rely on it? One example here is
> that a lot of the MMC drivers have an optional regulator to control some
> of the supplies for the cards. If the reglator isn't there it won't be
> used but it's not a blocker for anything. Devices doing this would need
> some way to figure out if they should -EBUSY or fail otherwise.
Just to avoid confusion - ITYM -EAGAIN there. -EBUSY is already used
by drivers to mean "someone else claimed a resource I need" be it the
IO region or an IRQ resource...
next prev parent reply other threads:[~2011-09-26 15:12 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-22 18:51 Grant Likely
2011-09-22 18:58 ` Joe Perches
2011-09-22 19:28 ` David Daney
2011-09-22 20:29 ` Alan Cox
2011-09-22 21:19 ` Grant Likely
2011-09-23 17:50 ` Valdis.Kletnieks
2011-09-23 23:18 ` Grant Likely
2011-09-22 21:19 ` David Daney
2011-09-22 22:47 ` Alan Cox
2011-09-23 5:02 ` Grant Likely
2011-09-23 16:55 ` David Daney
2011-09-26 14:16 ` Mark Brown
2011-09-26 15:12 ` Russell King - ARM Linux [this message]
2011-09-26 15:26 ` Mark Brown
2011-09-26 15:48 ` Grant Likely
2011-09-27 13:50 ` Arnd Bergmann
2011-09-27 21:08 ` Grant Likely
2011-09-27 22:13 ` Mark Brown
2011-09-28 13:04 ` Arnd Bergmann
2011-09-28 13:20 ` Mark Brown
2011-09-28 23:14 ` Grant Likely
2011-09-29 11:00 ` Mark Brown
2011-10-03 23:02 ` Kevin Hilman
2011-10-04 15:52 ` Grant Likely
2011-10-04 14:51 ` G, Manjunath Kondaiah
2011-10-04 15:58 ` Grant Likely
2011-10-04 18:35 ` G, Manjunath Kondaiah
2011-10-04 23:35 ` Grant Likely
2011-10-07 3:31 ` G, Manjunath Kondaiah
2011-10-11 20:47 ` Andrew Morton
2011-10-11 21:07 ` David Daney
2011-10-13 4:19 ` Grant Likely
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=20110926151210.GO22455@n2100.arm.linux.org.uk \
--to=linux@arm.linux.org.uk \
--cc=arnd@arndb.de \
--cc=broonie@opensource.wolfsonmicro.com \
--cc=dilee@nvidia.com \
--cc=grant.likely@secretlab.ca \
--cc=greg@kroah.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=manjunath.gkondaiah@linaro.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
all inboxes | Powered by JetHome®