Re: [RFC PATCH 00/11] Removing Calxeda platform support

From: Florian Fainelli
Date: Tue Feb 18 2020 - 13:51:33 EST

On 2/18/20 10:40 AM, Rob Herring wrote:
> On Tue, Feb 18, 2020 at 12:14 PM Andre Przywara <andre.przywara@xxxxxxx> wrote:
>> On Tue, 18 Feb 2020 11:13:10 -0600
>> Rob Herring <robh@xxxxxxxxxx> wrote:
>> Hi,
>>> Calxeda has been defunct for 6 years now. Use of Calxeda servers carried
>>> on for some time afterwards primarily as distro builders for 32-bit ARM.
>>> AFAIK, those systems have been retired in favor of 32-bit VMs on 64-bit
>>> hosts.
>>> The other use of Calxeda Midway I'm aware of was testing 32-bit ARM KVM
>>> support as there are few or no other systems with enough RAM and LPAE. Now
>>> 32-bit KVM host support is getting removed[1].
>>> While it's not much maintenance to support, I don't care to convert the
>>> Calxeda DT bindings to schema nor fix any resulting errors in the dts files
>>> (which already don't exactly match what's shipping in firmware).
>> While every kernel maintainer seems always happy to take patches with a negative diffstat, I wonder if this is really justification enough to remove a perfectly working platform. I don't really know about any active users, but experience tells that some platforms really are used for quite a long time, even if they are somewhat obscure. N900 or Netwinder, anyone?
>> So to not give the impression that actually *everyone* (from that small subset of people actively reading the kernel list) is happy with that, I think that having support for at least Midway would be useful. On the one hand it's a decent LPAE platform (with memory actually exceeding 4GB), and on the other hand it's something with capable I/O (SATA) and networking, so one can actually stress test the system. Which is the reason I was using that for KVM testing, but even with that probably going away now there remain still some use cases, and be it for general ARM(32) testing.
> Does LPAE with more than 4GB actually need to work if there's not
> another platform out there?

There are ARCH_BRCMSTB platforms that are 32-bit only and have 6GB of
DRAM populated, and those continue to work just fine, though there is no
known use for KVM AFAICT.