[PATCH] mlxsw: spectrum_ptp: release parsing depth on MTPPPC write failure

[PATCH] mlxsw: spectrum_ptp: release parsing depth on MTPPPC write failure

[Wentao Liang]

mlxsw_sp1_ptp_mtpppc_update() increases the global parsing depth
reference count before writing the MTPPPC register when timestamping
is enabled for the first time. If the register write fails, the
reference count remains elevated even though no timestamping
configuration was installed, and nothing will ever release it.

Drop the reference count again when the write fails. Also only drop it
when disabling timestamping after the write succeeded, so that the
reference count always matches the programmed state.

Fixes: c6b36bdd04b5 ("mlxsw: spectrum_ptp: Increase parsing depth when PTP is enabled")
Cc: stable@vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
index 9c5862f4e16a..0db77af4828f 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
@@ -1190,6 +1190,7 @@ static int mlxsw_sp1_ptp_mtpppc_update(struct mlxsw_sp_port *mlxsw_sp_port,
 	struct mlxsw_sp_port *tmp;
 	u16 orig_ing_types = 0;
 	u16 orig_egr_types = 0;
+	bool depth_inc = false;
 	int err;
 	int i;
 
@@ -1214,12 +1215,21 @@ static int mlxsw_sp1_ptp_mtpppc_update(struct mlxsw_sp_port *mlxsw_sp_port,
 			netdev_err(mlxsw_sp_port->dev, "Failed to increase parsing depth");
 			return err;
 		}
+		depth_inc = true;
 	}
+
+	err = mlxsw_sp1_ptp_mtpppc_set(mlxsw_sp_port->mlxsw_sp,
+				       ing_types, egr_types);
+	if (err) {
+		if (depth_inc)
+			mlxsw_sp_parsing_depth_dec(mlxsw_sp);
+		return err;
+	}
+
 	if (!(ing_types || egr_types) && (orig_ing_types || orig_egr_types))
 		mlxsw_sp_parsing_depth_dec(mlxsw_sp);
 
-	return mlxsw_sp1_ptp_mtpppc_set(mlxsw_sp_port->mlxsw_sp,
-				       ing_types, egr_types);
+	return 0;
 }
 
 static bool mlxsw_sp1_ptp_hwtstamp_enabled(struct mlxsw_sp_port *mlxsw_sp_port)
-- 
2.34.1

Re: [PATCH] mlxsw: spectrum_ptp: release parsing depth on MTPPPC write failure

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - How the issue was discovered, e.g. hit in production, hit during
   development, syzbot report, manual code inspection, LLM or static
   analysis tool scan.

 - Whether the issue was actually triggered, or is only theoretical
   (e.g. found by code inspection). If it was triggered please include
   the symptoms, like the stack trace or error messages.

 - What hardware the change was tested on. For driver fixes please
   mention the device (and if relevant firmware version) used for
   testing, or say that the change was not tested on real hardware.

Please do not repost the series just to address the above. Instead,
reply to this email with the missing information, so that reviewers
can take it into account. If the series needs another revision for
other reasons, please include the information in the commit messages
then.

The evaluation is done by an LLM so it may be wrong, if you think
that is the case please reply and explain.

Re: [PATCH] mlxsw: spectrum_ptp: release parsing depth on MTPPPC write failure

[Krzysztof Kozlowski]

On Tue, 03 Nov 2026 10:28:51 +0000, Wentao Liang wrote:
> mlxsw_sp1_ptp_mtpppc_update() increases the global parsing depth
> reference count before writing the MTPPPC register when timestamping
> is enabled for the first time. If the register write fails, the
> reference count remains elevated even though no timestamping
> configuration was installed, and nothing will ever release it.
> 
> Drop the reference count again when the write fails. Also only drop it
> when disabling timestamping after the write succeeded, so that the
> reference count always matches the programmed state.
> 
> Fixes: c6b36bdd04b5 ("mlxsw: spectrum_ptp: Increase parsing depth when PTP is enabled")
> Cc: stable@vger.kernel.org
> Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>  drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 



Multiple things here:
1. Your team ignored completely previous feedback. Multiple times.

2. You use multiple identities with this email address, thus I doubt that we
   speak with an actual person.

3. Your bot does not even bother running checkpatch, right?

4. Nothing of this was reproduced nor tested.

5. Finally, the same feedback:
You sent multiple independent patches, to multiple independent
subsystems. The amount of these patches clearly suggest this was
AI generated and most likely not tested.

More importantly, you sent all this work without properly organizing
relevant patches into patchsets. This makes reviewing difficult
and might cause multiple reviewers to address the same issue.
Replying to the entire set is impossible and requires handling each
patch independently, instead of applying or discarding the set.
Maintainers also won't see the bigger picture of your work. Quite
worrying.

This is on the verge of hostile patch: bomb us with so many
contributions, we won't be able to handle them in efficient manner,
like responding ONCE to ask you to slow down.  Considering all this
is untested and LLM generated, I have even more doubts whether this
should be considered for review.

Please read kernel documentation BEFORE posting more work. It will
explain you how to identify subsystems, how to organize your work per
subsystem (so a patchset grouping multiple patches with a short cover
letter), how to document the issue discovery method and what was
or was not tested.

Best regards,
Krzysztof

Re: [PATCH] mlxsw: spectrum_ptp: release parsing depth on MTPPPC write failure

[Krzysztof Kozlowski]

On Tue, 03 Nov 2026 10:28:51 +0000, Wentao Liang wrote:
> mlxsw_sp1_ptp_mtpppc_update() increases the global parsing depth
> reference count before writing the MTPPPC register when timestamping
> is enabled for the first time. If the register write fails, the
> reference count remains elevated even though no timestamping
> configuration was installed, and nothing will ever release it.
> 
> Drop the reference count again when the write fails. Also only drop it
> when disabling timestamping after the write succeeded, so that the
> reference count always matches the programmed state.
> 
> Fixes: c6b36bdd04b5 ("mlxsw: spectrum_ptp: Increase parsing depth when PTP is enabled")
> Cc: stable@vger.kernel.org
> Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>  drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 

Multiple things here:
1. Your team ignored completely previous feedback. Multiple times.

2. You use multiple identities with this email address, thus I doubt that we
   speak with an actual person.

3. Your bot does not even bother running checkpatch, right?

4. Nothing of this was reproduced nor tested.

5. Finally, the same feedback:
You sent multiple independent patches, to multiple independent
subsystems. The amount of these patches clearly suggest this was
AI generated and most likely not tested.

More importantly, you sent all this work without properly organizing
relevant patches into patchsets. This makes reviewing difficult
and might cause multiple reviewers to address the same issue.
Replying to the entire set is impossible and requires handling each
patch independently, instead of applying or discarding the set.
Maintainers also won't see the bigger picture of your work. Quite
worrying.

This is on the verge of hostile patch: bomb us with so many
contributions, we won't be able to handle them in efficient manner,
like responding ONCE to ask you to slow down.  Considering all this
is untested and LLM generated, I have even more doubts whether this
should be considered for review.

Please read kernel documentation BEFORE posting more work. It will
explain you how to identify subsystems, how to organize your work per
subsystem (so a patchset grouping multiple patches with a short cover
letter), how to document the issue discovery method and what was
or was not tested.

Best regards,
Krzysztof