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Message-ID: <33cf08b4fe751af156b1a7c17f69a0ca37dc5eed.camel@linux.ibm.com>
Subject: Re: [PATCH 2/2] MAINTAINERS: Make cxl obsolete
From: Andrew Donnellan <ajd@linux.ibm.com>
To: Michael Ellerman <michaele@au1.ibm.com>, 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 13:15:42 +1000
In-Reply-To: <87bk6jb17s.fsf@mail.lhotse>
References: <20240409031027.41587-1-ajd@linux.ibm.com>
	 <20240409031027.41587-2-ajd@linux.ibm.com> <87bk6jb17s.fsf@mail.lhotse>
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On Tue, 2024-04-09 at 14:37 +1000, Michael Ellerman wrote:
>=20
> Something like the patch below. Anyone who has an existing config and
> runs oldconfig will get a prompt, eg:
>=20
> =C2=A0 Deprecated support for IBM Coherent Accelerators (CXL)
> (DEPRECATED_CXL) [N/m/y/?] (NEW)
>=20
> Folks who just use defconfig etc. won't notice any change which is a
> pity. We could also change the default to n, but that risks breaking
> someone's machine. Maybe we do that in a another releases time.
>=20
> cheers
>=20
> diff --git a/drivers/misc/cxl/Kconfig b/drivers/misc/cxl/Kconfig
> index 5efc4151bf58..e3fd3fcaf62a 100644
> --- a/drivers/misc/cxl/Kconfig
> +++ b/drivers/misc/cxl/Kconfig
> @@ -9,11 +9,18 @@ config CXL_BASE
> =C2=A0	select PPC_64S_HASH_MMU
> =C2=A0
> =C2=A0config CXL
> -	tristate "Support for IBM Coherent Accelerators (CXL)"
> +	def_bool y
> +	depends on DEPRECATED_CXL
> +
> +config DEPRECATED_CXL
> +	tristate "Deprecated support for IBM Coherent Accelerators
> (CXL)"

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.

> =C2=A0	depends on PPC_POWERNV && PCI_MSI && EEH
> =C2=A0	select CXL_BASE
> =C2=A0	default m
> =C2=A0	help
> +	=C2=A0 The cxl driver is no longer actively maintained and we
> intend to
> +	=C2=A0 remove it in a future kernel release.
> +
> =C2=A0	=C2=A0 Select this option to enable driver support for IBM
> Coherent
> =C2=A0	=C2=A0 Accelerators (CXL).=C2=A0 CXL is otherwise known as Coheren=
t
> Accelerator
> =C2=A0	=C2=A0 Processor Interface (CAPI).=C2=A0 CAPI allows accelerators =
in
> FPGAs to be

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