Re: [PATCH RFC net-next v2 17/17] net: stmmac: pcs: Drop the _SHIFT macros

Russell King (Oracle)
2024-06-28T14:43:00Z

On Mon, Jun 24, 2024 at 04:26:34PM +0300, Serge Semin wrote:
> The PCS_ANE_PSE_SHIFT and PCS_ANE_RFE_SHIFT are unused anyway. Moreover
> PCS_ANE_PSE and PCS_ANE_RFE are the respective field masks. So the
> FIELD_GET()/FIELD_SET() macro-functions can be used to get/set the fields
> content. Drop the _SHIFT macros for good then.
>
> Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
> ---
> drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> index a17e5b37c411..0f15c9898788 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> @@ -43,9 +43,7 @@
> #define PCS_ANE_FD BIT(5) /* AN Full-duplex flag */
> #define PCS_ANE_HD BIT(6) /* AN Half-duplex flag */
> #define PCS_ANE_PSE GENMASK(8, 7) /* AN Pause Encoding */
> -#define PCS_ANE_PSE_SHIFT 7
> #define PCS_ANE_RFE GENMASK(13, 12) /* AN Remote Fault Encoding */
> -#define PCS_ANE_RFE_SHIFT 12
> #define PCS_ANE_ACK BIT(14) /* AN Base-page acknowledge */

I would actually like to see all these go away.

PCS_ANE_FD == LPA_1000XFULL
PCS_ANE_HD == LPA_1000XHALF
PCS_ANE_PSE == LPA_1000XPAUSE and LPA_1000XPAUSE_ASYM
PCS_ANE_RFE == LPA_RESV and LPA_RFAULT
PCS_ANE_ACK == LPA_LPACK

Isn't it rather weird that the field layout matches 802.3z aka
1000base-X and not SGMII? This layout would not make sense for Cisco
SGMII as it loses the speed information conveyed by the Cisco SGMII
control word.

This isn't a case of the manufacturer using "SGMII" to mean a serial
gigabit media independent interface that supports 1000base-X
(PHY_INTERFACE_MODE_1000BASEX) rather than Cisco SGMII
(PHY_INTERFACE_MODE_SGMII) ?

--
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