Re: [PATCH][next] scsi: pm80xx: Avoid -Wflex-array-member-not-at-end warning

[John Garry <john.g.garry@oracle.com>]

On 03/09/2025 19:44, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
> 
> Move the conflicting declarations to the end of the corresponding
> structures. Notice that `struct ssp_response_iu` is a flexible
> structure, this is a structure that contains a flexible-array member.
> 
> With these changes fix the following warnings:
> 
> drivers/scsi/pm8001/pm8001_hwi.h:342:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> drivers/scsi/pm8001/pm80xx_hwi.h:561:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> 
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>   drivers/scsi/pm8001/pm8001_hwi.h | 4 +++-
>   drivers/scsi/pm8001/pm80xx_hwi.h | 4 +++-
>   2 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/pm8001/pm8001_hwi.h b/drivers/scsi/pm8001/pm8001_hwi.h
> index fc2127dcb58d..7dc7870a8f86 100644
> --- a/drivers/scsi/pm8001/pm8001_hwi.h
> +++ b/drivers/scsi/pm8001/pm8001_hwi.h
> @@ -339,8 +339,10 @@ struct ssp_completion_resp {
>   	__le32	status;
>   	__le32	param;
>   	__le32	ssptag_rescv_rescpad;
> -	struct ssp_response_iu  ssp_resp_iu;
>   	__le32	residual_count;
> +
> +	/* Must be last --ends in a flexible-array member. */
> +	struct ssp_response_iu  ssp_resp_iu;

this is a HW structure, right? I did not think that it is ok to simply 
re-order them...

>   } __attribute__((packed, aligned(4)));
>   
>   
> diff --git a/drivers/scsi/pm8001/pm80xx_hwi.h b/drivers/scsi/pm8001/pm80xx_hwi.h
> index eb8fd37b2066..21afc28d9875 100644
> --- a/drivers/scsi/pm8001/pm80xx_hwi.h
> +++ b/drivers/scsi/pm8001/pm80xx_hwi.h
> @@ -558,8 +558,10 @@ struct ssp_completion_resp {
>   	__le32	status;
>   	__le32	param;
>   	__le32	ssptag_rescv_rescpad;
> -	struct ssp_response_iu ssp_resp_iu;
>   	__le32	residual_count;
> +
> +	/* Must be last --ends in a flexible-array member. */
> +	struct ssp_response_iu ssp_resp_iu;
>   } __attribute__((packed, aligned(4)));
>   
>   #define SSP_RESCV_BIT	0x00010000