diff mbox series

[RFC] net: macb: Process tx timestamp only on ptp packets

Message ID 20210824101238.21105-1-harini.katakam@xilinx.com
State New
Headers show
Series [RFC] net: macb: Process tx timestamp only on ptp packets | expand

Commit Message

Harini Katakam Aug. 24, 2021, 10:12 a.m. UTC 
The current implementation timestamps all packets and also processes
the BD timestamp for the same. While it is true that HWTSTAMP_TX_ON
enables timestamps for outgoing packets, the sender of the packet
i.e. linuxptp enables timestamp for PTP or PTP event packets. Cadence
GEM IP has a provision to enable this in HW only for PTP packets.
Enable this option in DMA BD settings register to decrease overhead.

Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Acked-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---
 drivers/net/ethernet/cadence/macb_ptp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Richard Cochran Aug. 25, 2021, 2:08 a.m. UTC | #1 
On Tue, Aug 24, 2021 at 08:59:20PM +0530, Harini Katakam wrote:
> Yes, there is no SW overhead because the  skb check ensures timestamp

> post processing is done only on requested packets. But the IP

> timestamps all packets

> because this is a register level setting, not per packet. That's the

> overhead I was referring to.


But the IP block time stamps the frames in silicon, no?

I don't see how that is "overhead" in any sense of the word.

Thanks,
Richard
diff mbox series

Patch

diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
index c2e1f163bb14..e4f26d972219 100644
--- a/drivers/net/ethernet/cadence/macb_ptp.c
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -471,7 +471,7 @@  int gem_set_hwtst(struct net_device *dev, struct ifreq *ifr, int cmd)
 			return -ERANGE;
 		fallthrough;
 	case HWTSTAMP_TX_ON:
-		tx_bd_control = TSTAMP_ALL_FRAMES;
+		tx_bd_control = TSTAMP_ALL_PTP_FRAMES;
 		break;
 	default:
 		return -ERANGE;