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Message-ID: <cc20a76f-6de5-b850-2c54-1e2a535feca6@infradead.org>
Date:   Tue, 17 Jan 2023 09:21:48 -0800
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Subject: Re: [PATCH 01/19] bus/cdx: add the cdx bus driver
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To:     Nipun Gupta <nipun.gupta@amd.com>, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, gregkh@linuxfoundation.org,
        rafael@kernel.org, eric.auger@redhat.com,
        alex.williamson@redhat.com, cohuck@redhat.com,
        song.bao.hua@hisilicon.com, mchehab+huawei@kernel.org,
        maz@kernel.org, f.fainelli@gmail.com, jeffrey.l.hugo@gmail.com,
        saravanak@google.com, Michael.Srba@seznam.cz, mani@kernel.org,
        yishaih@nvidia.com, jgg@ziepe.ca, jgg@nvidia.com,
        robin.murphy@arm.com, will@kernel.org, joro@8bytes.org,
        masahiroy@kernel.org, ndesaulniers@google.com,
        linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Cc:     okaya@kernel.org, harpreet.anand@amd.com, nikhil.agarwal@amd.com,
        michal.simek@amd.com, git@amd.com
References: <20230117134139.1298-1-nipun.gupta@amd.com>
 <20230117134139.1298-2-nipun.gupta@amd.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <20230117134139.1298-2-nipun.gupta@amd.com>
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Hi--

On 1/17/23 05:41, Nipun Gupta wrote:
> Introduce AMD CDX bus, which provides a mechanism for scanning
> and probing CDX devices. These devices are memory mapped on
> system bus for Application Processors(APUs).
> 
> CDX devices can be changed dynamically in the Fabric and CDX
> bus interacts with CDX controller to rescan the bus and
> rediscover the devices.
> 
> Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
> Signed-off-by: Tarak Reddy <tarak.reddy@amd.com>
> ---
>  Documentation/ABI/testing/sysfs-bus-cdx |  12 +
>  MAINTAINERS                             |   7 +
>  drivers/bus/Kconfig                     |   1 +
>  drivers/bus/Makefile                    |   2 +
>  drivers/bus/cdx/Kconfig                 |  14 +
>  drivers/bus/cdx/Makefile                |   8 +
>  drivers/bus/cdx/cdx.c                   | 433 ++++++++++++++++++++++++
>  drivers/bus/cdx/cdx.h                   |  62 ++++
>  include/linux/cdx/cdx_bus.h             | 153 +++++++++
>  include/linux/mod_devicetable.h         |  15 +
>  scripts/mod/devicetable-offsets.c       |   4 +
>  scripts/mod/file2alias.c                |  12 +
>  12 files changed, 723 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-cdx
>  create mode 100644 drivers/bus/cdx/Kconfig
>  create mode 100644 drivers/bus/cdx/Makefile
>  create mode 100644 drivers/bus/cdx/cdx.c
>  create mode 100644 drivers/bus/cdx/cdx.h
>  create mode 100644 include/linux/cdx/cdx_bus.h
> 

> diff --git a/drivers/bus/cdx/Kconfig b/drivers/bus/cdx/Kconfig
> new file mode 100644
> index 000000000000..54e0623ebcff
> --- /dev/null
> +++ b/drivers/bus/cdx/Kconfig
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# CDX bus configuration
> +#
> +# Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
> +#
> +
> +config CDX_BUS
> +	bool "CDX Bus driver"
> +	help
> +	  Driver to enable CDX Bus. CDX bus provides a mechanism for
> +	  scanning and probing of CDX devices. CDX devices are memory
> +	  mapped on system bus for embedded CPUs. CDX bus uses CDX
> +	  controller and firmware to scan the CDX devices.

Would you mind telling people who use 'make *config' what CDX means,
either in the bool prompt string or in the help text?


> +/**
> + * cdx_unregister_device - Unregister a CDX device
> + * @dev: CDX device
> + * @data: This is always passed as NULL, and is not used in this API,
> + *	  but is required here as the bus_for_each_dev() API expects
> + *	  the passed function (cdx_unregister_device) to have this
> + *	  as an argument.
> + *
> + * @return: -errno on failure, 0 on success.

The syntax (or spelling) for a function's return value in kernel-doc is just:
 * Return: -errno on failure, 0 on success.

That should be changed in many places throughout.

Thanks.

-- 
~Randy