| Message ID | 20220919183907.6689-1-vfedorenko@novek.ru (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] bnxt_en: replace reset with config timestamps | expand |
On Mon, Sep 19, 2022 at 11:39 AM Vadim Fedorenko <vfedorenko@novek.ru> wrote: > > 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. 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 | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c > index 8e316367f6ce..36e9148468b5 100644 > --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c > +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c > @@ -505,10 +505,8 @@ 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 (!rc && !ptp->tstamp_filters) > + bnxt_ptp_cfg_tstamp_filters(bp); > + if (!ptp->tstamp_filters) Closing and opening is the correct sequence, but this might work too. Please give us a day to review this. Thanks.
On Tue, Sep 20, 2022 at 7:36 AM Michael Chan <michael.chan@broadcom.com> wrote: > > On Mon, Sep 19, 2022 at 11:39 AM Vadim Fedorenko <vfedorenko@novek.ru> wrote: > > > > 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. 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 | 6 ++---- > > 1 file changed, 2 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c > > index 8e316367f6ce..36e9148468b5 100644 > > --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c > > +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c > > @@ -505,10 +505,8 @@ 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 (!rc && !ptp->tstamp_filters) > > + bnxt_ptp_cfg_tstamp_filters(bp); > > + if (!ptp->tstamp_filters) > > Closing and opening is the correct sequence, but this might work too. > Please give us a day to review this. Thanks. We have internally discussed this issue in great detail. If the user is changing the ALL_RX setting (enabling it or disabling it), just calling bnxt_ptp_cfg_tstamp_filters() is not sufficient. The reason is that there is no synchronization after we send the new setting to the FW. We don't know when valid timestamps will start showing up in the RX completion ring after turning on ALL_RX. That's why we need to close and open. After open, all RX packets are guaranteed to have valid timestamps. So what we can do is to detect any changes to ALL_RX setting. If ALL_RX is not changing, we can just do what this patch is doing. If ALL_RX is changing, we can do something less intrusive than close/open. We can just shutdown RX and restart RX. This way we don't have to toggle carrier and cause a bigger disruption. My colleague Pavan will take a few days to work on this. Thanks.
On 21.09.2022 22:33, Michael Chan wrote: > On Tue, Sep 20, 2022 at 7:36 AM Michael Chan <michael.chan@broadcom.com> wrote: >> >> On Mon, Sep 19, 2022 at 11:39 AM Vadim Fedorenko <vfedorenko@novek.ru> wrote: >>> >>> 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. 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 | 6 ++---- >>> 1 file changed, 2 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c >>> index 8e316367f6ce..36e9148468b5 100644 >>> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c >>> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c >>> @@ -505,10 +505,8 @@ 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 (!rc && !ptp->tstamp_filters) >>> + bnxt_ptp_cfg_tstamp_filters(bp); >>> + if (!ptp->tstamp_filters) >> >> Closing and opening is the correct sequence, but this might work too. >> Please give us a day to review this. Thanks. > > We have internally discussed this issue in great detail. If the user > is changing the ALL_RX setting (enabling it or disabling it), just > calling bnxt_ptp_cfg_tstamp_filters() is not sufficient. The reason > is that there is no synchronization after we send the new setting to > the FW. We don't know when valid timestamps will start showing up in > the RX completion ring after turning on ALL_RX. That's why we need to > close and open. After open, all RX packets are guaranteed to have > valid timestamps. > > So what we can do is to detect any changes to ALL_RX setting. If > ALL_RX is not changing, we can just do what this patch is doing. If > ALL_RX is changing, we can do something less intrusive than > close/open. We can just shutdown RX and restart RX. This way we > don't have to toggle carrier and cause a bigger disruption. > Thanks for the review. I got your point regarding timestamps for all RX packets, but for now I care about the case when ALL_RX is not supported. I can send a v2 with the check for this condition while you are working on the improvements for all cases. Will it be to review and commit such patch? Thanks.
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c index 8e316367f6ce..36e9148468b5 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c @@ -505,10 +505,8 @@ 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 (!rc && !ptp->tstamp_filters) + bnxt_ptp_cfg_tstamp_filters(bp); + if (!ptp->tstamp_filters) rc = -EIO; }
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. 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 | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)