On 06/08/2026 16:19, Willem de Bruijn wrote:
> Marcin Szycik wrote:
>>
>>
>> On 03/08/2026 23:06, Willem de Bruijn wrote:
>>> From: Willem de Bruijn <[email protected]>
>>>
>>> idpf_tx_splitq_build_flow_desc performs a 32-bit store to &cmd_dtype
>>> to set the 8-bit cmd_dtype and zero the adjacent 3-byte timestamp
>>> field in a single operation.
>>>
>>> Descriptors are in little endian. Add missing cpu_to_le32 and cast to
>>> __le32 to ensure the fields are written correctly also on big endian
>>> platforms.
>>>
>>> Fixes: 1a49cf814fe1 ("idpf: add Tx timestamp flows")
>>> Signed-off-by: Willem de Bruijn <[email protected]>
>>> Reviewed-by: Tony Nguyen <[email protected]>
>>>
>>> ---
>>>
>>> Changes
>>> v1 -> v2
>>> - add Fixes tag, Tony's Reviewed-by and Cc:
>>> [email protected]
>>> v1:
>>> https://lore.kernel.org/netdev/[email protected]/
>>> ---
>>> drivers/net/ethernet/intel/idpf/idpf_txrx.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
>>> b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
>>> index c724d429a7aa..91ca75e45463 100644
>>> --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
>>> +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
>>> @@ -2408,7 +2408,7 @@ void idpf_tx_splitq_build_flow_desc(union
>>> idpf_tx_flex_desc *desc,
>>> struct idpf_tx_splitq_params *params,
>>> u16 td_cmd, u16 size)
>>> {
>>> - *(u32 *)&desc->flow.qw1.cmd_dtype = (u8)(params->dtype | td_cmd);
>>> + *(__le32 *)&desc->flow.qw1.cmd_dtype = cpu_to_le32((u8)(params->dtype |
>>> td_cmd));
>>
>> While it technically works, I find it unreadable. Looking at this line
>> without reading commit msg, it looks like a bug where a 4-byte value is
>> written to u8 field. The intent to zero an adjacent, unrelated field is
>> not clear. Consider assigning these 4 fields manually, or adding a
>> comment/function doc.
>
> This is a bug fix, which generally should be the smallest surgical
> change only.
Agreed.
> That said, I do agree on the style, and a follow-up for net-next will
> clean that up too:
>
> @@ -2408,7 +2410,12 @@ void idpf_tx_splitq_build_flow_desc(union
> idpf_tx_flex_desc *desc,
> struct idpf_tx_splitq_params
> *params,
> u16 td_cmd, u16 size)
> {
> - *(__le32 *)&desc->flow.qw1.cmd_dtype =
> cpu_to_le32((u8)(params->dtype | td_cmd));
> + desc->flow.qw1.cmd_dtype = (u8)(params->dtype | td_cmd);
> +
> + desc->flow.qw1.ts[0] = params->offload.desc_ts[0];
> + desc->flow.qw1.ts[1] = params->offload.desc_ts[1];
> + desc->flow.qw1.ts[2] = params->offload.desc_ts[2];
>
> The fix is queued. If there is consensus, I can respin. But given that
> we will clean this up in net-next properly, my preference is to keep
> the minimal fix as is.
I'm fine with this. Was the cleanup patch already posted to next?
Thanks,
Marcin
