Re: [PATCH net-next v2 0/1] net: rnpgbe: fix mailbox endianness

[Paolo Abeni <pabeni@redhat.com>]

On 7/1/26 5:22 AM, Dong Yibo wrote:
> The rnpgbe mailbox exchanges data through 32-bit MMIO registers in
> little-endian wire format.  The original code had two problems:
> 
>  1. FW structs with __le16/__le32 fields were cast to (u32 *) before
>     reaching the transport, hiding the endian annotations from sparse.
> 
>  2. No cpu_to_le32()/le32_to_cpu() conversion was performed between
>     the CPU-endian MMIO values and the little-endian payload, causing
>     data corruption on big-endian systems.
> 
> v2 fixes this by introducing union wrappers around the FW structs
> and adding the missing byte-order conversions in the transport layer.
> All pointer casts on the mailbox data path are eliminated.
> 
> Changelog:
> v1 -> v2:
> - Remove all pointer casts on the mailbox data path.  Use union
>   wrappers (mbx_fw_cmd_req_u, mbx_fw_cmd_reply_u) that overlay
>   each FW struct with a __le32 dwords[] array.  Callers fill
>   named fields with cpu_to_le16/32() and pass dwords[] directly
>   to the transport — no casts needed.
> - Change transport signatures from u32 */void * to explicit
>   __le32 * so sparse can verify endian correctness.
> - Add comments in mucse_read_mbx_pf() and mucse_write_mbx_pf()
>   explaining why memcpy_toio() cannot replace the readl()/writel()
>   loop (the mailbox uses 32-bit MMIO registers, not byte-
>   addressable RAM).
> 
> links:
> ---
> v1: https://lore.kernel.org/netdev/20260617083531.251119-1-dong100@mucse.com/

A few process notes:
- this is 'net' material, I'm applying the patch there
- no needed for a cover letter for a one-patch series

/P