From: Greg KH <greg@kroah.com>
To: Grant Likely <grant.likely@secretlab.ca>
Cc: Dilan Lee <dilee@nvidia.com>,
Valdis.Kletnieks@vt.edu, Arnd Bergmann <arnd@arndb.de>,
"G, Manjunath Kondaiah" <manjugk@ti.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 1/5] drivercore: add new error value for deferred probe
Date: Sun, 9 Oct 2011 18:06:56 -0700 [thread overview]
Message-ID: <20111010010656.GA16537@kroah.com> (raw)
In-Reply-To: <CACxGe6t+PfnNGniYUj3pbK22uqjqkbh2+D=7qvvd_-Yd4yR0dw@mail.gmail.com>
On Sun, Oct 09, 2011 at 04:59:31PM -0600, Grant Likely wrote:
> On Fri, Oct 7, 2011 at 6:12 PM, Greg KH <greg@kroah.com> wrote:
> > On Fri, Oct 07, 2011 at 07:28:33PM -0400, Valdis.Kletnieks@vt.edu wrote:
> >> On Fri, 07 Oct 2011 16:12:45 MDT, Grant Likely said:
> >> > On Fri, Oct 7, 2011 at 12:43 AM, Greg KH <greg@kroah.com> wrote:
> >> > > On Fri, Oct 07, 2011 at 10:33:06AM +0500, G, Manjunath Kondaiah wrote:
> >>
> >> > >> +#define EPROBE_DEFER 517 /* restart probe again after some time */
> >> > >
> >> > > Can we really do this?
> >>
> >> > According to Arnd, yes this is okay.
> >>
> >> > > Isn't this some user/kernel api here?
> >>
> >> > > What's wrong with just "overloading" on top of an existing error code?
> >> > > Surely one of the other 516 types could be used here, right?
> >>
> >> > overloading makes it really hard to find the users at a later date.
> >>
> >> Would proposing '#define EPROBE_DEFER EAGAIN' be acceptable to everybody? That
> >> would allow overloading EAGAIN, but still make it easy to tell the usages apart
> >> if we need to separate them later...
> >
> > Yes, please do that, it is what USB does for it's internal error code
> > handling.
>
> Really? When we've only currently used approximately 2^9 of a 2^31
> numberspace? I'm fine with making sure that the number doesn't show
> up in the userspace headers, but it makes no sense to overload the
> #defines. Particularly so in this case where it isn't feasible to
> audit every driver to figure out what probe might possibly return. It
> is well within the realm of possibility that existing drivers are
> already returning -EAGAIN.
I doubt they are, but you are right, it's really hard to tell.
> Besides; linux/errno.h *already* has linux-internal error codes that
> do not get exported out to userspace. There is an #ifdef __KERNEL__
> block around ERESTARTSYS through EIOCBRETRY which is filtered out when
> exporting headers. I can't see any possible reason why we wouldn't
> add Linux internal error codes here.
As long as it stays internal, that's fine, I was worried that this would
be exported to userspace.
Alan, still object to this?
greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: greg@kroah.com (Greg KH)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/5] drivercore: add new error value for deferred probe
Date: Sun, 9 Oct 2011 18:06:56 -0700 [thread overview]
Message-ID: <20111010010656.GA16537@kroah.com> (raw)
In-Reply-To: <CACxGe6t+PfnNGniYUj3pbK22uqjqkbh2+D=7qvvd_-Yd4yR0dw@mail.gmail.com>
On Sun, Oct 09, 2011 at 04:59:31PM -0600, Grant Likely wrote:
> On Fri, Oct 7, 2011 at 6:12 PM, Greg KH <greg@kroah.com> wrote:
> > On Fri, Oct 07, 2011 at 07:28:33PM -0400, Valdis.Kletnieks at vt.edu wrote:
> >> On Fri, 07 Oct 2011 16:12:45 MDT, Grant Likely said:
> >> > On Fri, Oct 7, 2011 at 12:43 AM, Greg KH <greg@kroah.com> wrote:
> >> > > On Fri, Oct 07, 2011 at 10:33:06AM +0500, G, Manjunath Kondaiah wrote:
> >>
> >> > >> +#define EPROBE_DEFER 517 ? ? /* restart probe again after some time */
> >> > >
> >> > > Can we really do this?
> >>
> >> > According to Arnd, yes this is okay.
> >>
> >> > > ?Isn't this some user/kernel api here?
> >>
> >> > > What's wrong with just "overloading" on top of an existing error code?
> >> > > Surely one of the other 516 types could be used here, right?
> >>
> >> > overloading makes it really hard to find the users at a later date.
> >>
> >> Would proposing '#define EPROBE_DEFER EAGAIN' be acceptable to everybody? That
> >> would allow overloading EAGAIN, but still make it easy to tell the usages apart
> >> if we need to separate them later...
> >
> > Yes, please do that, it is what USB does for it's internal error code
> > handling.
>
> Really? When we've only currently used approximately 2^9 of a 2^31
> numberspace? I'm fine with making sure that the number doesn't show
> up in the userspace headers, but it makes no sense to overload the
> #defines. Particularly so in this case where it isn't feasible to
> audit every driver to figure out what probe might possibly return. It
> is well within the realm of possibility that existing drivers are
> already returning -EAGAIN.
I doubt they are, but you are right, it's really hard to tell.
> Besides; linux/errno.h *already* has linux-internal error codes that
> do not get exported out to userspace. There is an #ifdef __KERNEL__
> block around ERESTARTSYS through EIOCBRETRY which is filtered out when
> exporting headers. I can't see any possible reason why we wouldn't
> add Linux internal error codes here.
As long as it stays internal, that's fine, I was worried that this would
be exported to userspace.
Alan, still object to this?
greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: Greg KH <greg@kroah.com>
To: Grant Likely <grant.likely@secretlab.ca>
Cc: Valdis.Kletnieks@vt.edu, "G, Manjunath Kondaiah" <manjugk@ti.com>,
linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org,
linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
Dilan Lee <dilee@nvidia.com>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
Manjunath GKondaiah <manjunath.gkondaiah@linaro.org>,
Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH 1/5] drivercore: add new error value for deferred probe
Date: Sun, 9 Oct 2011 18:06:56 -0700 [thread overview]
Message-ID: <20111010010656.GA16537@kroah.com> (raw)
In-Reply-To: <CACxGe6t+PfnNGniYUj3pbK22uqjqkbh2+D=7qvvd_-Yd4yR0dw@mail.gmail.com>
On Sun, Oct 09, 2011 at 04:59:31PM -0600, Grant Likely wrote:
> On Fri, Oct 7, 2011 at 6:12 PM, Greg KH <greg@kroah.com> wrote:
> > On Fri, Oct 07, 2011 at 07:28:33PM -0400, Valdis.Kletnieks@vt.edu wrote:
> >> On Fri, 07 Oct 2011 16:12:45 MDT, Grant Likely said:
> >> > On Fri, Oct 7, 2011 at 12:43 AM, Greg KH <greg@kroah.com> wrote:
> >> > > On Fri, Oct 07, 2011 at 10:33:06AM +0500, G, Manjunath Kondaiah wrote:
> >>
> >> > >> +#define EPROBE_DEFER 517 /* restart probe again after some time */
> >> > >
> >> > > Can we really do this?
> >>
> >> > According to Arnd, yes this is okay.
> >>
> >> > > Isn't this some user/kernel api here?
> >>
> >> > > What's wrong with just "overloading" on top of an existing error code?
> >> > > Surely one of the other 516 types could be used here, right?
> >>
> >> > overloading makes it really hard to find the users at a later date.
> >>
> >> Would proposing '#define EPROBE_DEFER EAGAIN' be acceptable to everybody? That
> >> would allow overloading EAGAIN, but still make it easy to tell the usages apart
> >> if we need to separate them later...
> >
> > Yes, please do that, it is what USB does for it's internal error code
> > handling.
>
> Really? When we've only currently used approximately 2^9 of a 2^31
> numberspace? I'm fine with making sure that the number doesn't show
> up in the userspace headers, but it makes no sense to overload the
> #defines. Particularly so in this case where it isn't feasible to
> audit every driver to figure out what probe might possibly return. It
> is well within the realm of possibility that existing drivers are
> already returning -EAGAIN.
I doubt they are, but you are right, it's really hard to tell.
> Besides; linux/errno.h *already* has linux-internal error codes that
> do not get exported out to userspace. There is an #ifdef __KERNEL__
> block around ERESTARTSYS through EIOCBRETRY which is filtered out when
> exporting headers. I can't see any possible reason why we wouldn't
> add Linux internal error codes here.
As long as it stays internal, that's fine, I was worried that this would
be exported to userspace.
Alan, still object to this?
greg k-h
next prev parent reply other threads:[~2011-10-10 1:06 UTC|newest]
Thread overview: 116+ 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 6:43 ` Greg KH
2011-10-07 10:00 ` Mark Brown
2011-10-07 10:00 ` Mark Brown
2011-10-07 22:12 ` Grant Likely
2011-10-07 22:12 ` Grant Likely
2011-10-07 23:28 ` Valdis.Kletnieks
2011-10-07 23:28 ` Valdis.Kletnieks
2011-10-07 23:28 ` Valdis.Kletnieks at vt.edu
2011-10-08 0:12 ` Greg KH
2011-10-08 0:12 ` Greg KH
2011-10-09 22:59 ` Grant Likely
2011-10-09 22:59 ` Grant Likely
2011-10-09 22:59 ` Grant Likely
2011-10-10 1:06 ` Greg KH [this message]
2011-10-10 1:06 ` Greg KH
2011-10-10 1:06 ` Greg KH
2011-10-12 6:18 ` G, Manjunath Kondaiah
2011-10-12 6:18 ` G, Manjunath Kondaiah
2011-10-13 4:10 ` Grant Likely
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 6:49 ` Greg KH
2011-10-07 20:57 ` Josh Triplett
2011-10-07 20:57 ` Josh Triplett
2011-10-07 21:23 ` Greg KH
2011-10-07 21:23 ` Greg KH
2011-10-08 4:03 ` Josh Triplett
2011-10-08 4:03 ` Josh Triplett
2011-10-08 15:55 ` Greg KH
2011-10-08 15:55 ` Greg KH
2011-10-08 18:18 ` Josh Triplett
2011-10-08 18:18 ` Josh Triplett
2011-10-10 17:37 ` Andrei Warkentin
2011-10-10 17:37 ` Andrei Warkentin
2011-10-11 12:29 ` Ming Lei
2011-10-11 12:29 ` Ming Lei
2011-10-13 4:09 ` Grant Likely
2011-10-13 4:09 ` Grant Likely
2011-10-13 14:18 ` Ming Lei
2011-10-13 14:18 ` Ming Lei
2011-10-13 14:31 ` Alan Stern
2011-10-13 14:31 ` Alan Stern
2011-10-13 14:31 ` Alan Stern
2011-10-13 15:21 ` Ming Lei
2011-10-13 15:21 ` Ming Lei
2011-10-13 16:04 ` Alan Stern
2011-10-13 16:04 ` Alan Stern
2011-10-13 16:04 ` Alan Stern
2011-10-14 0:13 ` Ming Lei
2011-10-14 0:13 ` Ming Lei
2011-10-13 17:15 ` Grant Likely
2011-10-13 17:15 ` Grant Likely
2011-10-13 18:16 ` Alan Stern
2011-10-13 18:16 ` Alan Stern
2011-10-13 18:16 ` Alan Stern
2011-10-13 18:28 ` Grant Likely
2011-10-13 18:28 ` Grant Likely
2011-10-14 15:39 ` Alan Stern
2011-10-14 15:39 ` Alan Stern
2011-10-14 15:39 ` Alan Stern
2011-10-14 16:17 ` Grant Likely
2011-10-14 16:17 ` Grant Likely
2011-10-14 16:33 ` Alan Stern
2011-10-14 16:33 ` Alan Stern
2011-10-14 16:33 ` Alan Stern
2011-10-14 17:20 ` Grant Likely
2011-10-14 17:20 ` Grant Likely
2011-10-14 17:33 ` Alan Stern
2011-10-14 17:33 ` Alan Stern
2011-10-14 17:33 ` Alan Stern
2011-10-14 18:25 ` Grant Likely
2011-10-14 18:25 ` Grant Likely
2011-10-14 18:39 ` Alan Stern
2011-10-14 18:39 ` Alan Stern
2011-10-14 18:39 ` Alan Stern
2011-10-14 19:07 ` Grant Likely
2011-10-14 19:07 ` Grant Likely
2011-10-14 18:56 ` David Daney
2011-10-14 18:56 ` David Daney
2011-10-14 19:03 ` Grant Likely
2011-10-14 19:03 ` Grant Likely
2011-10-14 19:03 ` Grant Likely
2011-10-14 19:09 ` David Daney
2011-10-14 19:09 ` David Daney
2011-10-14 15:37 ` Alan Stern
2011-10-14 15:37 ` Alan Stern
2011-10-14 15:37 ` Alan Stern
2011-10-12 7:04 ` G, Manjunath Kondaiah
2011-10-12 7:04 ` G, Manjunath Kondaiah
2011-10-07 21:28 ` Grant Likely
2011-10-07 21:28 ` Grant Likely
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 10:06 ` Alan Cox
2011-10-07 10:06 ` Alan Cox
2011-10-07 22:09 ` Grant Likely
2011-10-07 22:09 ` Grant Likely
2011-10-12 6:14 ` G, Manjunath Kondaiah
2011-10-12 6:14 ` G, Manjunath Kondaiah
2011-10-12 6:14 ` G, Manjunath Kondaiah
2011-10-13 4:12 ` Grant Likely
2011-10-13 4:12 ` Grant Likely
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 6:50 ` Greg KH
2011-10-07 6:50 ` Greg KH
2011-10-07 7:37 ` G, Manjunath Kondaiah
2011-10-07 7:37 ` G, Manjunath Kondaiah
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 1/5] drivercore: add new error value for deferred probe G, Manjunath Kondaiah
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