Re: [PATCH 2/2] MAINTAINERS: Make cxl obsolete

[Andrew Donnellan <ajd@linux.ibm.com>]

On Tue, 2024-04-09 at 14:37 +1000, Michael Ellerman wrote:
> 
> Something like the patch below. Anyone who has an existing config and
> runs oldconfig will get a prompt, eg:
> 
>   Deprecated support for IBM Coherent Accelerators (CXL)
> (DEPRECATED_CXL) [N/m/y/?] (NEW)
> 
> 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.
> 
> cheers
> 
> 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
>  	select PPC_64S_HASH_MMU
>  
>  config 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.

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 +	  The cxl driver is no longer actively maintained and we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

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