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.
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.
