From: Grant Likely <grant.likely@secretlab.ca>
To: "G, Manjunath Kondaiah" <manjugk@ti.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, Dilan Lee <dilee@nvidia.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <greg@kroah.com>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
Manjunath GKondaiah <manjunath.gkondaiah@linaro.org>,
linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 4/5] gpiolib: handle deferral probe error
Date: Wed, 12 Oct 2011 22:12:50 -0600 [thread overview]
Message-ID: <20111013041250.GG15829@ponder.secretlab.ca> (raw)
In-Reply-To: <20111012061432.GA2080@manju-desktop>
On Wed, Oct 12, 2011 at 11:44:32AM +0530, G, Manjunath Kondaiah wrote:
> On Fri, Oct 07, 2011 at 04:09:38PM -0600, Grant Likely wrote:
> > On Fri, Oct 7, 2011 at 4:06 AM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> > > On Fri, 07 Oct 2011 10:33:09 +0500
> > > "G, Manjunath Kondaiah" <manjugk@ti.com> wrote:
> > >
> > >>
> > >> The gpio library should return -EPROBE_DEFER in gpio_request
> > >> if gpio driver is not ready.
> > >
> > > Why not use the perfectly good existing error codes we have for this ?
> > >
> > > We have EAGAIN and EUNATCH both of which look sensible.
> >
> > I want a distinct error code for probe deferral so that a) it doesn't
> > overlap with something a driver is already doing, and b) so that all
> > the users can be found again at a later date.
> >
> > That said, I'm not in agreement with this patch. It is fine for gpio
> > lib to have a code that means the pin doesn't exist (yet), but the
> > device driver needs to be the one to decide whether or not it is
> > appropriate to use probe deferral.
>
> During gpio_request, driver gpio_request is not available. How can we expect
> driver to request deferred probe in this case?
If gpio_request fails, the driver can then explicitly make the
decision to return -EPROBE_DEFER. It isn't forced to pass on the
error code from gpio_request().
g.
next prev parent reply other threads:[~2011-10-13 4:12 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-07 5:33 [PATCH 0/5] Driver Probe Deferral Mechanism G, Manjunath Kondaiah
2011-10-07 5:33 ` [PATCH 1/5] drivercore: add new error value for deferred probe G, Manjunath Kondaiah
2011-10-07 6:43 ` Greg KH
2011-10-07 10:00 ` Mark Brown
2011-10-07 22:12 ` Grant Likely
2011-10-07 23:28 ` Valdis.Kletnieks
2011-10-08 0:12 ` Greg KH
2011-10-09 22:59 ` Grant Likely
2011-10-10 1:06 ` Greg KH
2011-10-12 6:18 ` G, Manjunath Kondaiah
2011-10-13 4:10 ` Grant Likely
2011-10-07 5:33 ` [PATCH 2/5] drivercore: Add driver probe deferral mechanism G, Manjunath Kondaiah
2011-10-07 6:49 ` Greg KH
2011-10-07 20:57 ` Josh Triplett
2011-10-07 21:23 ` Greg KH
2011-10-08 4:03 ` Josh Triplett
2011-10-08 15:55 ` Greg KH
2011-10-08 18:18 ` Josh Triplett
2011-10-10 17:37 ` Andrei Warkentin
2011-10-11 12:29 ` Ming Lei
2011-10-13 4:09 ` Grant Likely
2011-10-13 14:18 ` Ming Lei
2011-10-13 14:31 ` Alan Stern
2011-10-13 15:21 ` Ming Lei
2011-10-13 16:04 ` Alan Stern
2011-10-14 0:13 ` Ming Lei
2011-10-13 17:15 ` Grant Likely
2011-10-13 18:16 ` Alan Stern
2011-10-13 18:28 ` Grant Likely
2011-10-14 15:39 ` Alan Stern
2011-10-14 16:17 ` Grant Likely
2011-10-14 16:33 ` Alan Stern
2011-10-14 17:20 ` Grant Likely
2011-10-14 17:33 ` Alan Stern
2011-10-14 18:25 ` Grant Likely
2011-10-14 18:39 ` Alan Stern
2011-10-14 19:07 ` Grant Likely
2011-10-14 18:56 ` David Daney
2011-10-14 19:03 ` Grant Likely
2011-10-14 19:09 ` David Daney
2011-10-14 15:37 ` Alan Stern
2011-10-12 7:04 ` G, Manjunath Kondaiah
2011-10-07 21:28 ` Grant Likely
2011-10-07 5:33 ` [PATCH 3/5] regulator: Support driver probe deferral G, Manjunath Kondaiah
2011-10-07 5:33 ` [PATCH 4/5] gpiolib: handle deferral probe error G, Manjunath Kondaiah
2011-10-07 10:06 ` Alan Cox
2011-10-07 22:09 ` Grant Likely
2011-10-12 6:14 ` G, Manjunath Kondaiah
2011-10-13 4:12 ` Grant Likely [this message]
2011-10-07 5:33 ` [PATCH 5/5] omap: hsmmc: use platform_driver_register G, Manjunath Kondaiah
2011-10-07 6:50 ` [PATCH 0/5] Driver Probe Deferral Mechanism Greg KH
2011-10-07 7:37 ` G, Manjunath Kondaiah
-- strict thread matches above, loose matches on Subject: below --
2011-10-07 5:05 G, Manjunath Kondaiah
2011-10-07 5:05 ` [PATCH 4/5] gpiolib: handle deferral probe error G, Manjunath Kondaiah
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