[PATCH][next] net: spacemit: Avoid -Wflex-array-member-not-at-end warnings

[PATCH][next] net: spacemit: Avoid -Wflex-array-member-not-at-end warnings

[Gustavo A. R. Silva]

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Use regular arrays instead of flexible-array members (they're not
really needed in this case) in a couple of unions, and fix the
following warnings:

      1 drivers/net/ethernet/spacemit/k1_emac.c:122:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
      1 drivers/net/ethernet/spacemit/k1_emac.c:122:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
      1 drivers/net/ethernet/spacemit/k1_emac.c:121:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
      1 drivers/net/ethernet/spacemit/k1_emac.c:121:32: 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/net/ethernet/spacemit/k1_emac.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/spacemit/k1_emac.h b/drivers/net/ethernet/spacemit/k1_emac.h
index 5a09e946a276..577efe66573e 100644
--- a/drivers/net/ethernet/spacemit/k1_emac.h
+++ b/drivers/net/ethernet/spacemit/k1_emac.h
@@ -363,7 +363,7 @@ struct emac_desc {
 /* Keep stats in this order, index used for accessing hardware */
 
 union emac_hw_tx_stats {
-	struct {
+	struct individual_tx_stats {
 		u64 tx_ok_pkts;
 		u64 tx_total_pkts;
 		u64 tx_ok_bytes;
@@ -378,11 +378,11 @@ union emac_hw_tx_stats {
 		u64 tx_pause_pkts;
 	} stats;
 
-	DECLARE_FLEX_ARRAY(u64, array);
+	u64 array[sizeof(struct individual_tx_stats) / sizeof(u64)];
 };
 
 union emac_hw_rx_stats {
-	struct {
+	struct individual_rx_stats {
 		u64 rx_ok_pkts;
 		u64 rx_total_pkts;
 		u64 rx_crc_err_pkts;
@@ -410,7 +410,7 @@ union emac_hw_rx_stats {
 		u64 rx_truncate_fifo_full_pkts;
 	} stats;
 
-	DECLARE_FLEX_ARRAY(u64, array);
+	u64 array[sizeof(struct individual_rx_stats) / sizeof(u64)];
 };
 
 #endif /* _K1_EMAC_H_ */
-- 
2.43.0

Re: [PATCH][next] net: spacemit: Avoid -Wflex-array-member-not-at-end warnings

[Simon Horman]

On Tue, Oct 21, 2025 at 12:54:10PM +0100, 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.
> 
> Use regular arrays instead of flexible-array members (they're not
> really needed in this case) in a couple of unions, and fix the
> following warnings:
> 
>       1 drivers/net/ethernet/spacemit/k1_emac.c:122:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>       1 drivers/net/ethernet/spacemit/k1_emac.c:122:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>       1 drivers/net/ethernet/spacemit/k1_emac.c:121:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>       1 drivers/net/ethernet/spacemit/k1_emac.c:121:32: 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>

Thanks,

I was able to reproduce the above build warnings.
And agree that this patch addresses them.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH][next] net: spacemit: Avoid -Wflex-array-member-not-at-end warnings

[Vivian Wang]

Hi Gustavo,

Thanks for the patch.

On 10/21/25 19:54, 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.
>
> Use regular arrays instead of flexible-array members (they're not
> really needed in this case) in a couple of unions, and fix the
> following warnings:
>
>       1 drivers/net/ethernet/spacemit/k1_emac.c:122:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>       1 drivers/net/ethernet/spacemit/k1_emac.c:122:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>       1 drivers/net/ethernet/spacemit/k1_emac.c:121:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>       1 drivers/net/ethernet/spacemit/k1_emac.c:121:32: 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/net/ethernet/spacemit/k1_emac.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/spacemit/k1_emac.h b/drivers/net/ethernet/spacemit/k1_emac.h
> index 5a09e946a276..577efe66573e 100644
> --- a/drivers/net/ethernet/spacemit/k1_emac.h
> +++ b/drivers/net/ethernet/spacemit/k1_emac.h
> @@ -363,7 +363,7 @@ struct emac_desc {
>  /* Keep stats in this order, index used for accessing hardware */
>  
>  union emac_hw_tx_stats {
> -	struct {
> +	struct individual_tx_stats {
>  		u64 tx_ok_pkts;
>  		u64 tx_total_pkts;
>  		u64 tx_ok_bytes;
> @@ -378,11 +378,11 @@ union emac_hw_tx_stats {
>  		u64 tx_pause_pkts;
>  	} stats;
>  
> -	DECLARE_FLEX_ARRAY(u64, array);
> +	u64 array[sizeof(struct individual_tx_stats) / sizeof(u64)];

I originally wrote it as DECLARE_FLEX_ARRAY to avoid having to do the
sizeof dance, but I guess that's no good now? Oh well, I guess...

Acked-by: Vivian Wang <wangruikang@iscas.ac.cn>

Re: [PATCH][next] net: spacemit: Avoid -Wflex-array-member-not-at-end warnings

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 21 Oct 2025 12:54:10 +0100 you wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
> 
> Use regular arrays instead of flexible-array members (they're not
> really needed in this case) in a couple of unions, and fix the
> following warnings:
> 
> [...]

Here is the summary with links:
  - [next] net: spacemit: Avoid -Wflex-array-member-not-at-end warnings
    https://git.kernel.org/netdev/net-next/c/10e0378f05d2

You are awesome, thank you!
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