Re: [PATCH RFC] ARM: BCM5301X: Add /device_id property including device ID string

[Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>]

On Monday 30 March 2015 11:58:29 Mark Rutland wrote:
> > > 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.

Sorry for jumping in late here, but this still sounds like more fitting
for the "compatible" property than "model". For compatible, you can
already have multiple strings, and they come with a vendor prefix.

Any of these would seem reasonable to me:

a)
        compatible = "asus,rt-ac68u", "openwrt,RT-AC68U", "brcm,bcm4708";
        model = "Asus RT-AC68U (BCM4708)";

b)
        compatible = "asus,rt-ac68u", "brcm,RT-AC68U", "brcm,bcm4708";
        model = "Asus RT-AC68U (BCM4708)";

c)
        compatible = "asus,rt-ac68u", "asus,RT-AC68U", "brcm,bcm4708";
        model = "Asus RT-AC68U (BCM4708)";

depending on which party maintains the list of these identifiers.

	Arnd
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