Re: [PATCH net-next 4/4] net: macb: Clear SRTSM outside PTPv2 receive filters

[Nicolai Buchwitz <nb@tipi-net.de>]

On 22.9.2026 11:10, Kim Wooseok via B4 Relay wrote:
> From: Kim Wooseok <5mghybrid@khu.ac.kr>
> 
> A PTPv2 receive filter sets NCR.SRTSM, but switching to NONE, ALL or a
> PTPv1 filter leaves it set. As a result, selecting the same filter can
> produce a different register setting depending on whether PTPv2 was
> used before.
> 
> Update SRTSM whenever the RX filter changes, setting it only for PTPv2.
> Switching away from PTPv2 then clears the old setting, so the bit 
> follows
> the currently selected filter.
> 
> Assisted-by: GPT-6 Astra
> Signed-off-by: Kim Wooseok <5mghybrid@khu.ac.kr>
> ---
>  drivers/net/ethernet/cadence/macb_ptp.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_ptp.c 
> b/drivers/net/ethernet/cadence/macb_ptp.c
> index 6376b6631..637d0da32 100644
> --- a/drivers/net/ethernet/cadence/macb_ptp.c
> +++ b/drivers/net/ethernet/cadence/macb_ptp.c
> @@ -390,7 +390,7 @@ int gem_set_hwtst(struct net_device *netdev,
>  		  struct kernel_hwtstamp_config *tstamp_config,
>  		  struct netlink_ext_ack *extack)
>  {
> -	u32 ncr_mask = MACB_BIT(OSSMODE);
> +	u32 ncr_mask = MACB_BIT(OSSMODE) | MACB_BIT(SRTSM);
>  	enum macb_bd_control tx_bd_control = TSTAMP_DISABLED;
>  	enum macb_bd_control rx_bd_control = TSTAMP_DISABLED;
>  	int rx_filter = tstamp_config->rx_filter;
> @@ -429,7 +429,6 @@ int gem_set_hwtst(struct net_device *netdev,
>  	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
>  		rx_bd_control = TSTAMP_ALL_PTP_FRAMES;
>  		rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
> -		ncr_mask |= MACB_BIT(SRTSM);
>  		ncr_bits |= MACB_BIT(SRTSM);
>  		break;
>  	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai