Message-ID: <b1f0ed44-d707-5593-7449-8a6bd23c9902@acm.org>
Date:   Wed, 22 Feb 2023 07:25:42 -0800
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Subject: Re: [PATCH 1/2] include: uapi: scsi: Change utp_upiu_query struct
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To:     Arthur Simchaev <Arthur.Simchaev@wdc.com>,
        martin.petersen@oracle.com
Cc:     beanhuo@micron.com, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1677078770-30994-1-git-send-email-Arthur.Simchaev@wdc.com>
 <1677078770-30994-2-git-send-email-Arthur.Simchaev@wdc.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <1677078770-30994-2-git-send-email-Arthur.Simchaev@wdc.com>
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On 2/22/23 07:12, Arthur Simchaev wrote:
> diff --git a/include/uapi/scsi/scsi_bsg_ufs.h b/include/uapi/scsi/scsi_bsg_ufs.h
> index 2801b65..cccc07d 100644
> --- a/include/uapi/scsi/scsi_bsg_ufs.h
> +++ b/include/uapi/scsi/scsi_bsg_ufs.h
> @@ -54,20 +54,21 @@ struct utp_upiu_header {
>    * @idn: a value that indicates the particular type of data B-1
>    * @index: Index to further identify data B-2
>    * @selector: Index to further identify data B-3
> - * @reserved_osf: spec reserved field B-4,5
> - * @length: number of descriptor bytes to read/write B-6,7
> - * @value: Attribute value to be written DW-5
> - * @reserved: spec reserved DW-6,7
> + * @osf4: spec field B-5
> + * @osf5: spec field B 6,7
> + * @osf6: spec field DW 8,9
> + * @osf7: spec field DW 10,11
>    */
>   struct utp_upiu_query {
>   	__u8 opcode;
>   	__u8 idn;
>   	__u8 index;
>   	__u8 selector;
> -	__be16 reserved_osf;
> -	__be16 length;
> -	__be32 value;
> -	__be32 reserved[2];
> +	__u8 osf3;
> +	__u8 osf4;
> +	__be16 osf5;
> +	__be32 osf6;
> +	__be32 osf7;
>   };

All changes in UAPI headers must be backwards compatible. The above 
doesn't look like a backwards compatible change to me.

Bart.