All of lore.kernel.org
 help / color / mirror / Atom feed
From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH RFC] ARM: BCM5301X: Add /device_id property including device ID string
Date: Mon, 30 Mar 2015 11:58:29 +0100	[thread overview]
Message-ID: <20150330105828.GE17971@leverpostej> (raw)
In-Reply-To: <CACna6rykQq6AVSWzJh3qnHVNzPXbTD9TMGQf9D9p50pcbQkmng@mail.gmail.com>

> > On Sun, Mar 29, 2015 at 11:14:48PM +0100, Rafa? Mi?ecki wrote:
> >> Device vendors often assign IDs to their devices to allow comparing
> >> firmware image with device model. This is required to prevent users
> >> from flashing incompatible image and soft-bricking device.
> >> Add device_id property to DTs to allow user space (and optionally
> >> bootloader) verifying firmware images.
> >
> > This sounds like exactly what the "model" property is meant to be (per
> > ePAPR) -- a string that specifices the manufacturer's model number of
> > the device, ideally in "manufacturer,model" format.
> 
> What if manufacturer decided to use some totally unfriendly ID for
> their low-level (firmware upgrade) model identification? I can't
> really see us using
> model = "U12H245T00_NETGEAR"
> which would mean nothing compared to the current friendly:
> model = "Netgear R6250 V1 (BCM4708)"

If it uniquely identifies the model, it's fit to be a model string. If
being "friendly" means that we lose that, then the property is useless
anyway.

Note that both examples above deviate from the recommended format, and
something like: "netgear,U12H245T00" would better align with the
recommendation.

Mark.

WARNING: multiple messages have this Message-ID (diff)
From: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
To: "Rafał Miłecki" <zajec5-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
	<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
	Hauke Mehrtens <hauke-5/S+JYg5SzeELgA04lAiVw@public.gmane.org>,
	Florian Fainelli
	<f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>,
	Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>,
	"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH RFC] ARM: BCM5301X: Add /device_id property including device ID string
Date: Mon, 30 Mar 2015 11:58:29 +0100	[thread overview]
Message-ID: <20150330105828.GE17971@leverpostej> (raw)
In-Reply-To: <CACna6rykQq6AVSWzJh3qnHVNzPXbTD9TMGQf9D9p50pcbQkmng-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

> > On Sun, Mar 29, 2015 at 11:14:48PM +0100, Rafał Miłecki wrote:
> >> Device vendors often assign IDs to their devices to allow comparing
> >> firmware image with device model. This is required to prevent users
> >> from flashing incompatible image and soft-bricking device.
> >> Add device_id property to DTs to allow user space (and optionally
> >> bootloader) verifying firmware images.
> >
> > This sounds like exactly what the "model" property is meant to be (per
> > ePAPR) -- a string that specifices the manufacturer's model number of
> > the device, ideally in "manufacturer,model" format.
> 
> What if manufacturer decided to use some totally unfriendly ID for
> their low-level (firmware upgrade) model identification? I can't
> really see us using
> model = "U12H245T00_NETGEAR"
> which would mean nothing compared to the current friendly:
> model = "Netgear R6250 V1 (BCM4708)"

If it uniquely identifies the model, it's fit to be a model string. If
being "friendly" means that we lose that, then the property is useless
anyway.

Note that both examples above deviate from the recommended format, and
something like: "netgear,U12H245T00" would better align with the
recommendation.

Mark.
--
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

  reply	other threads:[~2015-03-30 10:58 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-29 22:14 [PATCH RFC] ARM: BCM5301X: Add /device_id property including device ID string Rafał Miłecki
2015-03-29 22:36 ` Russell King - ARM Linux
2015-03-29 22:54   ` Rafał Miłecki
2015-03-29 23:10     ` Russell King - ARM Linux
2015-03-30 10:37 ` Mark Rutland
2015-03-30 10:37   ` Mark Rutland
2015-03-30 10:43   ` Rafał Miłecki
2015-03-30 10:43     ` Rafał Miłecki
2015-03-30 10:58     ` Mark Rutland [this message]
2015-03-30 10:58       ` Mark Rutland
2015-04-10 10:50       ` Arnd Bergmann
2015-04-10 10:50         ` Arnd Bergmann
2015-04-10 10:55         ` Rafał Miłecki
2015-04-10 10:55           ` Rafał Miłecki

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150330105828.GE17971@leverpostej \
    --to=mark.rutland@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.