From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan@agner.ch (Stefan Agner) Date: Thu, 16 Apr 2015 21:40:55 +0200 Subject: [PATCH 1/2] Documentation: devicetree: root node serial-number property documentation In-Reply-To: <1429208077.2563.14.camel@collins> References: <1427564371-26039-1-git-send-email-contact@paulk.fr> <1429175421.2483.1.camel@collins> <1429199145.2563.9.camel@collins> <1429208077.2563.14.camel@collins> Message-ID: <97473e9075df185ab3024db70c471f53@agner.ch> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2015-04-16 20:14, Paul Kocialkowski wrote: > Le jeudi 16 avril 2015 ? 10:53 -0500, Kumar Gala a ?crit : >> > On Apr 16, 2015, at 10:45 AM, Paul Kocialkowski wrote: >> > >> > Le jeudi 16 avril 2015 ? 10:23 -0500, Kumar Gala a ?crit : >> >>> On Apr 16, 2015, at 9:36 AM, Rob Herring wrote: >> >>> >> >>> On Thu, Apr 16, 2015 at 4:10 AM, Paul Kocialkowski wrote: >> >>>> Le jeudi 16 avril 2015 ? 09:56 +0200, Stefan Agner a ?crit : >> >>>>> On 2015-03-28 18:39, Paul Kocialkowski wrote: >> >>>>>> Signed-off-by: Paul Kocialkowski >> >>>>> >> >>>>> I think this is a worthwhile standardization. >> >>>>> >> >>>>> Acked-by: Stefan Agner >> >>>> >> >>>> Thanks! I should also add a commit message in v2 mentioning that this is >> >>>> already used in open firmware and reported by lshw. >> >>> >> >>> With that, >> >>> >> >>> Acked-by: Rob Herring >> > >> > [snip] >> > >> >> I feel like this is a little lite either in the doc or commit message. >> >> Is the string completely arbitrary? Is it meant to match labeling on >> >> a board or case? Is this meant to be used by the kernel at all? >> > >> > I guess it doesn't really matter what it is, as long as it's a string. >> > The kernel does not suggest any use for it either, it's just made >> > available to userspace through cpuinfo. >> > >> > Now if there is a particular use for this in user-space, it would have >> > to match some standards. For instance, it Android, ro.serialno is >> > usually a 16-bytes (plus one null byte) representation of a 64 bit >> > number. For USB, I recall it is usually a 32 bytes string (including the >> > null byte), but may be extended to more. >> > >> > What the string actually represents depends and some SOCs have serial >> > number bytes (I know that omap and sunxi have some for instance, that >> > are usually used) while other devices may take it from somewhere else. >> > In any case, it doesn't really matter and is not up to the kernel anyway >> > since it is just passed through from the bootloader. >> > >> > Thus, I don't think it's very relevant to mention it in either the >> > documentation or the commit message. >> >> So you say ?board? in the patch, since it could be SoC specific, we >> should probably clean up the wording a bit. > > It really doesn't matter where the string comes from, what it contains > or whether some SoCs have provisions to generate one. > I think board is one the most common words that we can use to describe > devices. "devices" is also fine, I could go with it if you prefer, but I > don't really see what it changes. There is already something related for SoC's in SoC bus called soc_id, see Documentation/ABI/testing/sysfs-devices-soc So I would rather prefer that this is more reserved for device/board serial number... -- Stefan From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Agner Subject: Re: [PATCH 1/2] Documentation: devicetree: root node serial-number property documentation Date: Thu, 16 Apr 2015 21:40:55 +0200 Message-ID: <97473e9075df185ab3024db70c471f53@agner.ch> References: <1427564371-26039-1-git-send-email-contact@paulk.fr> <1429175421.2483.1.camel@collins> <1429199145.2563.9.camel@collins> <1429208077.2563.14.camel@collins> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1429208077.2563.14.camel@collins> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Paul Kocialkowski Cc: Kumar Gala , Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Russell King , Pawel Moll , Ian Campbell , Hans De Goede , Rob Herring , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 2015-04-16 20:14, Paul Kocialkowski wrote: > Le jeudi 16 avril 2015 =C3=A0 10:53 -0500, Kumar Gala a =C3=A9crit : >> > On Apr 16, 2015, at 10:45 AM, Paul Kocialkowski = wrote: >> > >> > Le jeudi 16 avril 2015 =C3=A0 10:23 -0500, Kumar Gala a =C3=A9crit= : >> >>> On Apr 16, 2015, at 9:36 AM, Rob Herring = wrote: >> >>> >> >>> On Thu, Apr 16, 2015 at 4:10 AM, Paul Kocialkowski wrote: >> >>>> Le jeudi 16 avril 2015 =C3=A0 09:56 +0200, Stefan Agner a =C3=A9= crit : >> >>>>> On 2015-03-28 18:39, Paul Kocialkowski wrote: >> >>>>>> Signed-off-by: Paul Kocialkowski >> >>>>> >> >>>>> I think this is a worthwhile standardization. >> >>>>> >> >>>>> Acked-by: Stefan Agner >> >>>> >> >>>> Thanks! I should also add a commit message in v2 mentioning tha= t this is >> >>>> already used in open firmware and reported by lshw. >> >>> >> >>> With that, >> >>> >> >>> Acked-by: Rob Herring >> > >> > [snip] >> > >> >> I feel like this is a little lite either in the doc or commit mes= sage. >> >> Is the string completely arbitrary? Is it meant to match labelin= g on >> >> a board or case? Is this meant to be used by the kernel at all? >> > >> > I guess it doesn't really matter what it is, as long as it's a str= ing. >> > The kernel does not suggest any use for it either, it's just made >> > available to userspace through cpuinfo. >> > >> > Now if there is a particular use for this in user-space, it would = have >> > to match some standards. For instance, it Android, ro.serialno is >> > usually a 16-bytes (plus one null byte) representation of a 64 bit >> > number. For USB, I recall it is usually a 32 bytes string (includi= ng the >> > null byte), but may be extended to more. >> > >> > What the string actually represents depends and some SOCs have ser= ial >> > number bytes (I know that omap and sunxi have some for instance, t= hat >> > are usually used) while other devices may take it from somewhere e= lse. >> > In any case, it doesn't really matter and is not up to the kernel = anyway >> > since it is just passed through from the bootloader. >> > >> > Thus, I don't think it's very relevant to mention it in either the >> > documentation or the commit message. >> >> So you say =E2=80=98board=E2=80=99 in the patch, since it could be S= oC specific, we >> should probably clean up the wording a bit. >=20 > It really doesn't matter where the string comes from, what it contain= s > or whether some SoCs have provisions to generate one. > I think board is one the most common words that we can use to describ= e > devices. "devices" is also fine, I could go with it if you prefer, bu= t I > don't really see what it changes. There is already something related for SoC's in SoC bus called soc_id, see Documentation/ABI/testing/sysfs-devices-soc So I would rather prefer that this is more reserved for device/board serial number... -- Stefan -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html