[PATCH net v2] bnxt_en: replace reset with config timestamps

[PATCH net v2] bnxt_en: replace reset with config timestamps

[Vadim Fedorenko]

Any change to the hardware timestamps configuration triggers nic restart,
which breaks transmition and reception of network packets for a while.
But there is no need to fully restart the device because while configuring
hardware timestamps. The code for changing configuration runs after all
of the initialisation, when the NIC is actually up and running. This patch
changes the code that ioctl will only update configuration registers and
will not trigger carrier status change, but in case of timestamps for
all rx packetes it fallbacks to close()/open() sequnce because of
synchronization issues in the hardware. Tested on BCM57504.

Fixes: 11862689e8f1 ("bnxt_en: Configure ptp filters during bnxt open")
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
index 8e316367f6ce..8c8492ee406a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
@@ -505,9 +505,12 @@ static int bnxt_hwrm_ptp_cfg(struct bnxt *bp)
 	ptp->tstamp_filters = flags;
 
 	if (netif_running(bp->dev)) {
-		rc = bnxt_close_nic(bp, false, false);
-		if (!rc)
-			rc = bnxt_open_nic(bp, false, false);
+		if (ptp->rx_filter == PORT_MAC_CFG_REQ_FLAGS_ALL_RX_TS_CAPTURE_ENABLE) {
+			rc = bnxt_close_nic(bp, false, false);
+			if (!rc)
+				rc = bnxt_open_nic(bp, false, false);
+		} else
+			bnxt_ptp_cfg_tstamp_filters(bp);
 		if (!rc && !ptp->tstamp_filters)
 			rc = -EIO;
 	}
-- 
2.27.0

Re: [PATCH net v2] bnxt_en: replace reset with config timestamps

[Jakub Kicinski]

On Thu, 22 Sep 2022 01:44:30 +0300 Vadim Fedorenko wrote:
> +		if (ptp->rx_filter == PORT_MAC_CFG_REQ_FLAGS_ALL_RX_TS_CAPTURE_ENABLE) {

Doesn't ptp->rx_filter hold the uAPI values, i.e. HWTSTAMP_FILTER_* ?

> +			rc = bnxt_close_nic(bp, false, false);
> +			if (!rc)
> +				rc = bnxt_open_nic(bp, false, false);
> +		} else
> +			bnxt_ptp_cfg_tstamp_filters(bp);

nit: missing brackets around the else branch

Re: [PATCH net v2] bnxt_en: replace reset with config timestamps

[Jakub Kicinski]

On Thu, 22 Sep 2022 01:44:30 +0300 Vadim Fedorenko wrote:
> Fixes: 11862689e8f1 ("bnxt_en: Configure ptp filters during bnxt open")

Also, I'd re-target at net-next, unfortunately resetting a NIC 
on random config changes is fairly common, we can't claim it's 
a bug :(

Re: [PATCH net v2] bnxt_en: replace reset with config timestamps

[Vadim Fedorenko]

On 22.09.2022 01:38, Jakub Kicinski wrote:
> On Thu, 22 Sep 2022 01:44:30 +0300 Vadim Fedorenko wrote:
>> +		if (ptp->rx_filter == PORT_MAC_CFG_REQ_FLAGS_ALL_RX_TS_CAPTURE_ENABLE) {
> 
> Doesn't ptp->rx_filter hold the uAPI values, i.e. HWTSTAMP_FILTER_* ?
> 

Thanks for catching this, Jakub.
>> +			rc = bnxt_close_nic(bp, false, false);
>> +			if (!rc)
>> +				rc = bnxt_open_nic(bp, false, false);
>> +		} else
>> +			bnxt_ptp_cfg_tstamp_filters(bp);
> 
> nit: missing brackets around the else branch

v3 is on the way, also moving to net-next and without Fixes tag