Messages in this thread | | | Date | Wed, 12 Oct 2011 11:48:23 +0530 | From | "G, Manjunath Kondaiah" <> | Subject | Re: [PATCH 1/5] drivercore: add new error value for deferred probe |
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On Sun, Oct 09, 2011 at 06:06:56PM -0700, Greg KH wrote: > 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?
I hope no one has objections to use EPROBE_DEFER
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