Re: [RESEND PATCH 2/9] dt-bindings: arm64: bcmbca: Update BCM4908 description

From: Rafał Miłecki
Date: Thu Jul 21 2022 - 03:58:47 EST


On 2022-07-21 09:36, Krzysztof Kozlowski wrote:
On 21/07/2022 09:13, Rafał Miłecki wrote:
That's better argument. But what's the benefit of adding generic
compatible? Devices cannot bind to it (it is too generic). Does it
describe the device anyhow? Imagine someone adding compatible
"brcm,all-soc-of-broadcom" - does it make any sense?

OK, I see it now. I can't think of any case of handling all devices
covered with suc a wide brcm,bcmbca binding.

Maybe there is some common part of a SoC which that generic compatible
would express?

Most archs don't use soc-wide generic compatible, because of reasons I
mentioned - no actual benefits for anyone from such compatible.

But there are exceptions. I fouun socfpga and apple. The apple sounds as
mistake to me, because the generic "apple,arm-platform" compatible looks
like covering all possible Apple ARM platforms. I think Apple ARM
designs in 20 years will not be compatible at all with current design,
so such broad compatible is not useful... but that's only my opinion.

Let's see if William / Broadcom guys can provide a valid argument for
the brcm,bcmbca.


This leads me to another question if we should actually totally drop
brcm,bcmbca from other SoCs bindings, see linux-next's
Documentation/devicetree/bindings/arm/bcm/brcm,bcmbca.yaml

This would be tricky as it was already accepted, unless all sit in
linux-next and did not make to v5.19-rc1.

5.19-rc7 has only 1 case with brcm,bcmbca, see ff6992735ade7
("Linux 5.19-rc7"):
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/arm/bcm/brcm,bcmbca.yaml?id=ff6992735ade75aae3e35d16b17da1008d753d28

So we can still clean it up for the 5.20-rc1 or 5.20-rc2.