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Message-ID: <2492716e18c515e21b855305c0bc760057dbcf7a.camel@linux.ibm.com>
Subject: Re: [PATCH 2/2] MAINTAINERS: Make cxl obsolete
From: Andrew Donnellan <ajd@linux.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@lists.ozlabs.org,
        linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Cc: manoj@linux.ibm.com, ukrishn@linux.ibm.com, fbarrat@linux.ibm.com
Date: Fri, 03 May 2024 17:55:03 +1000
In-Reply-To: <33cf08b4fe751af156b1a7c17f69a0ca37dc5eed.camel@linux.ibm.com>
References: <20240409031027.41587-1-ajd@linux.ibm.com>
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On Fri, 2024-05-03 at 13:15 +1000, Andrew Donnellan wrote:
> This doesn't seem quite right to me, I don't think we can just
> redefine
> CONFIG_CXL as a bool, but I'll do something like this. Probably won't
> bother for CXLFLASH since they'll see it for CXL anyway, but I might
> add a warning message on probe to both drivers.

The more I look at how to do this, the more issues I see, though
perhaps because I personally use olddefconfig more than I use
oldconfig.

Without changing the default to n, running olddefconfig is liable to
switch CXL back on in configs where the user has disabled it.

Conversely, if the user has set CXL=3Dy rather than CXL=3Dm, I'm not sure
if there's any way to make it such that olddefconfig doesn't reset one
symbol or the other to the default m.

Honestly, I'm very tempted to be a little more aggressive and a) not
bother with trying to play games with symbols, b) change the default to
n in this release, c) add a warning printed on probe, and see whether
anyone complains.

We could also print a message during the build itself, though that kind
of noise is liable to break things in other ways?

It would be kind of nice if kbuild had some way to mark a symbol for
deprecation which could print a warning during configuration.

--=20
Andrew Donnellan    OzLabs, ADL Canberra
ajd@linux.ibm.com   IBM Australia Limited