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Date:   Tue, 17 Nov 2020 17:57:58 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Bongsu Jeon <bongsu.jeon@samsung.com>
Cc:     "davem@davemloft.net" <davem@davemloft.net>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net-next] net/nfc/nci: Support NCI 2.x initial sequence
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On Tue, 17 Nov 2020 14:37:59 +0900 Bongsu Jeon wrote:
> implement the NCI 2.x initial sequence to support NCI 2.x NFCC.
> Since NCI 2.0, CORE_RESET and CORE_INIT sequence have been changed.
> If NFCEE supports NCI 2.x, then NCI 2.x initial sequence will work.
> 
> In NCI 1.0, Initial sequence and payloads are as below:
> (DH)                     (NFCC)
>  |  -- CORE_RESET_CMD --> |
>  |  <-- CORE_RESET_RSP -- |
>  |  -- CORE_INIT_CMD -->  |
>  |  <-- CORE_INIT_RSP --  |
>  CORE_RESET_RSP payloads are Status, NCI version, Configuration Status.
>  CORE_INIT_CMD payloads are empty.
>  CORE_INIT_RSP payloads are Status, NFCC Features,
>     Number of Supported RF Interfaces, Supported RF Interface,
>     Max Logical Connections, Max Routing table Size,
>     Max Control Packet Payload Size, Max Size for Large Parameters,
>     Manufacturer ID, Manufacturer Specific Information.
> 
> In NCI 2.0, Initial Sequence and Parameters are as below:
> (DH)                     (NFCC)
>  |  -- CORE_RESET_CMD --> |
>  |  <-- CORE_RESET_RSP -- |
>  |  <-- CORE_RESET_NTF -- |
>  |  -- CORE_INIT_CMD -->  |
>  |  <-- CORE_INIT_RSP --  |
>  CORE_RESET_RSP payloads are Status.
>  CORE_RESET_NTF payloads are Reset Trigger,
>     Configuration Status, NCI Version, Manufacturer ID,
>     Manufacturer Specific Information Length,
>     Manufacturer Specific Information.
>  CORE_INIT_CMD payloads are Feature1, Feature2.
>  CORE_INIT_RSP payloads are Status, NFCC Features,
>     Max Logical Connections, Max Routing Table Size,
>     Max Control Packet Payload Size,
>     Max Data Packet Payload Size of the Static HCI Connection,
>     Number of Credits of the Static HCI Connection,
>     Max NFC-V RF Frame Size, Number of Supported RF Interfaces,
>     Supported RF Interfaces.
> 
> Signed-off-by: Bongsu Jeon <bongsu.jeon@samsung.com>

Please fix the following sparse (build with C=1) warning:

net/nfc/nci/ntf.c:42:17: warning: cast to restricted __le32

> +	__u8 status = 0;

Please don't use the __u types in the normal kernel code, those are
types for user space ABI.