| Message ID | 20240125134104.2045573-1-leitao@debian.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 281cb9d65a95c00bb844f332cd187491d2d55496 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] bnxt_en: Make PTP timestamp HWRM more silent | expand |
On Thu, Jan 25, 2024 at 7:11 PM Breno Leitao <leitao@debian.org> wrote: > > commit 056bce63c469 ("bnxt_en: Make PTP TX timestamp HWRM query silent") > changed a netdev_err() to netdev_WARN_ONCE(). > > netdev_WARN_ONCE() is it generates a kernel WARNING, which is bad, for > the following reasons: > > * You do not a kernel warning if the firmware queries are late > * In busy networks, timestamp query failures fairly regularly > * A WARNING message doesn't bring much value, since the code path > is clear. > (This was discussed in-depth in [1]) > > Transform the netdev_WARN_ONCE() into a netdev_warn_once(), and print a > more well-behaved message, instead of a full WARN(). > > bnxt_en 0000:67:00.0 eth0: TS query for TX timer failed rc = fffffff5 > > [1] Link: https://lore.kernel.org/all/ZbDj%2FFI4EJezcfd1@gmail.com/ > Signed-off-by: Breno Leitao <leitao@debian.org> LGTM, however, you may still need to add a proper fixes tag.
On Thu, Jan 25, 2024 at 08:03:18PM +0530, Pavan Chebbi wrote: > On Thu, Jan 25, 2024 at 7:11 PM Breno Leitao <leitao@debian.org> wrote: > > > > commit 056bce63c469 ("bnxt_en: Make PTP TX timestamp HWRM query silent") > > changed a netdev_err() to netdev_WARN_ONCE(). > > > > netdev_WARN_ONCE() is it generates a kernel WARNING, which is bad, for > > the following reasons: > > > > * You do not a kernel warning if the firmware queries are late > > * In busy networks, timestamp query failures fairly regularly > > * A WARNING message doesn't bring much value, since the code path > > is clear. > > (This was discussed in-depth in [1]) > > > > Transform the netdev_WARN_ONCE() into a netdev_warn_once(), and print a > > more well-behaved message, instead of a full WARN(). > > > > bnxt_en 0000:67:00.0 eth0: TS query for TX timer failed rc = fffffff5 > > > > [1] Link: https://lore.kernel.org/all/ZbDj%2FFI4EJezcfd1@gmail.com/ > > Signed-off-by: Breno Leitao <leitao@debian.org> > > LGTM, however, you may still need to add a proper fixes tag. Thanks. I didn't include a fix tag because it is not a fix per se, but, I can easily send a v2 if this is needed.
On Thu, Jan 25, 2024 at 8:23 PM Breno Leitao <leitao@debian.org> wrote: > > On Thu, Jan 25, 2024 at 08:03:18PM +0530, Pavan Chebbi wrote: > > On Thu, Jan 25, 2024 at 7:11 PM Breno Leitao <leitao@debian.org> wrote: > > > > > > commit 056bce63c469 ("bnxt_en: Make PTP TX timestamp HWRM query silent") > > > changed a netdev_err() to netdev_WARN_ONCE(). > > > > > > netdev_WARN_ONCE() is it generates a kernel WARNING, which is bad, for > > > the following reasons: > > > > > > * You do not a kernel warning if the firmware queries are late > > > * In busy networks, timestamp query failures fairly regularly > > > * A WARNING message doesn't bring much value, since the code path > > > is clear. > > > (This was discussed in-depth in [1]) > > > > > > Transform the netdev_WARN_ONCE() into a netdev_warn_once(), and print a > > > more well-behaved message, instead of a full WARN(). > > > > > > bnxt_en 0000:67:00.0 eth0: TS query for TX timer failed rc = fffffff5 > > > > > > [1] Link: https://lore.kernel.org/all/ZbDj%2FFI4EJezcfd1@gmail.com/ > > > Signed-off-by: Breno Leitao <leitao@debian.org> > > > > LGTM, however, you may still need to add a proper fixes tag. > > Thanks. I didn't include a fix tag because it is not a fix per se, but, > I can easily send a v2 if this is needed. You have a point. But then in that case it should go to net-next, I think. If you respin or otherwise, Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
On Thu, 25 Jan 2024 20:51:25 +0530 Pavan Chebbi wrote: > > > LGTM, however, you may still need to add a proper fixes tag. > > > > Thanks. I didn't include a fix tag because it is not a fix per se, but, > > I can easily send a v2 if this is needed. We should pick it as a fix. If we put it in net-next and someone complains cherry-picking it into net would be a PITA. And we shouldn't spew WARN()s about known-to-be-occurring conditions, GregKH is pretty clear about that. If you can post the Fixes tag in a reply our apply scripts should pick it up automatically. Or at least mine will :)
On Thu, Jan 25, 2024 at 9:44 AM Jakub Kicinski <kuba@kernel.org> wrote: > > On Thu, 25 Jan 2024 20:51:25 +0530 Pavan Chebbi wrote: > > > > LGTM, however, you may still need to add a proper fixes tag. > > > > > > Thanks. I didn't include a fix tag because it is not a fix per se, but, > > > I can easily send a v2 if this is needed. > > We should pick it as a fix. If we put it in net-next and someone > complains cherry-picking it into net would be a PITA. And we shouldn't > spew WARN()s about known-to-be-occurring conditions, GregKH is pretty > clear about that. > > If you can post the Fixes tag in a reply our apply scripts should pick > it up automatically. Or at least mine will :) Fixes: 056bce63c469 ("bnxt_en: Make PTP TX timestamp HWRM query silent") Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 25 Jan 2024 05:41:03 -0800 you wrote: > commit 056bce63c469 ("bnxt_en: Make PTP TX timestamp HWRM query silent") > changed a netdev_err() to netdev_WARN_ONCE(). > > netdev_WARN_ONCE() is it generates a kernel WARNING, which is bad, for > the following reasons: > > * You do not a kernel warning if the firmware queries are late > * In busy networks, timestamp query failures fairly regularly > * A WARNING message doesn't bring much value, since the code path > is clear. > (This was discussed in-depth in [1]) > > [...] Here is the summary with links: - [net] bnxt_en: Make PTP timestamp HWRM more silent https://git.kernel.org/netdev/net/c/281cb9d65a95 You are awesome, thank you!
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c index adad188e38b8..cc07660330f5 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c @@ -684,7 +684,7 @@ static void bnxt_stamp_tx_skb(struct bnxt *bp, struct sk_buff *skb) timestamp.hwtstamp = ns_to_ktime(ns); skb_tstamp_tx(ptp->tx_skb, ×tamp); } else { - netdev_WARN_ONCE(bp->dev, + netdev_warn_once(bp->dev, "TS query for TX timer failed rc = %x\n", rc); }
commit 056bce63c469 ("bnxt_en: Make PTP TX timestamp HWRM query silent") changed a netdev_err() to netdev_WARN_ONCE(). netdev_WARN_ONCE() is it generates a kernel WARNING, which is bad, for the following reasons: * You do not a kernel warning if the firmware queries are late * In busy networks, timestamp query failures fairly regularly * A WARNING message doesn't bring much value, since the code path is clear. (This was discussed in-depth in [1]) Transform the netdev_WARN_ONCE() into a netdev_warn_once(), and print a more well-behaved message, instead of a full WARN(). bnxt_en 0000:67:00.0 eth0: TS query for TX timer failed rc = fffffff5 [1] Link: https://lore.kernel.org/all/ZbDj%2FFI4EJezcfd1@gmail.com/ Signed-off-by: Breno Leitao <leitao@debian.org> --- drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)