From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Wiklander Subject: Re: [PATCH v14 3/5] tee: add OP-TEE driver Date: Tue, 24 Jan 2017 13:53:31 +0100 Message-ID: <20170124125330.GA30998@jax> References: <1484744296-30003-1-git-send-email-jens.wiklander@linaro.org> <8183743.bSJXZpMh95@wuerfel> <20170123090852.GB1910@jax> <5564439.UZohRc66aK@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <5564439.UZohRc66aK@wuerfel> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Arnd Bergmann Cc: Greg Kroah-Hartman , Olof Johansson , Andrew Morton , Wei Xu , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Al Viro , valentin.manea-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, jean-michel.delorme-qxv4g6HH51o@public.gmane.org, emmanuel.michel-qxv4g6HH51o@public.gmane.org, javier-5MUHepqpBA1BDgjK7y7TUQ@public.gmane.org, Jason Gunthorpe , Mark Rutland , Michal Simek , Rob Herring , Will Deacon , Nishanth Menon , "Andrew F . Davis" , broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, scott.branden-dY08KVG/lbpWk0Htik3J/w@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, Jan 23, 2017 at 05:16:15PM +0100, Arnd Bergmann wrote: > On Monday, January 23, 2017 10:08:53 AM CET Jens Wiklander wrote: > > On Fri, Jan 20, 2017 at 05:57:51PM +0100, Arnd Bergmann wrote: > > > On Thursday, January 19, 2017 3:56:23 PM CET Jens Wiklander wrote: > > > > On Wed, Jan 18, 2017 at 05:28:17PM +0100, Arnd Bergmann wrote: > > > > > Does the platform devices really need cleaning? I mean > > > > of_platform_default_populate_init() creates a bunch of platform devices > > > > which are just left there even if unused. Here we're doing the same > > > > thing except that we're doing it for a specific node in the DT. > > > > > > I think it will work if you don't clean them up, but it feels wrong > > > to have a loadable module that creates devices when loaded but doesn't > > > remove them when unloaded. > > > > > > This could be done differently by having the device creation done in > > > one driver and the the user of that device in another driver, but I > > > think just killing off the device achieves the same in a simpler way. > > > > I see your point. My final concern here is that with device we got > > entries in sysfs and uevents that could be used to automatically start > > the correct supplicant. Different drivers are likely to require > > different supplicants. Starting the correct supplicant based on uevents > > is a quite elegant solution which I'm not sure how to support when > > skipping devices. Perhaps I could create an object below > > /firmware/tee ? > > Putting the objects somewhere other than /sys/devices sounds good, yes. > This would also help with TEE implementations that might get probed > differently. > > I think the natural place would be /sys/class/tee/, as we normally > require something in /sys/class anyway to support the character > device. > > /sys/firmware/tee/ sounds less fitting, as there other TEE implementations > are not necessarily firmware based, as you point out. > /sys/firmware/op-tee certainly makes sense for anything that is specific > to OP-TEE in particular, while /sys/class/tee would be for anything > that uses the ioctl interface. This part is particularly important to > get right from the start, just like the ioctls themselves we can't make > incompatible changes here later once there are users relying on the > upstream kernel interfaces. /sys/class/tee/ sounds good, I'll use that. It's more or less what we also have today. Thanks for the help with this review. Jens -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html