[PATCH AUTOSEL 6.6 58/62] octeontx2-pf: Add error log forcn10k_map_unmap_rq_policer()

[Sasha Levin <sashal@kernel.org>]

From: Wentao Liang <vulab@iscas.ac.cn>

[ Upstream commit 9c056ec6dd1654b1420dafbbe2a69718850e6ff2 ]

The cn10k_free_matchall_ipolicer() calls the cn10k_map_unmap_rq_policer()
for each queue in a for loop without checking for any errors.

Check the return value of the cn10k_map_unmap_rq_policer() function during
each loop, and report a warning if the function fails.

Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250408032602.2909-1-vulab@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

**YES** Based on my analysis of the commit and the surrounding codebase
context, this commit should be backported to stable kernel trees. Here's
my extensive analysis: ## Code Analysis ### The Specific Change The
commit adds error checking to a loop in `cn10k_free_matchall_ipolicer()`
that was previously ignoring return values from
`cn10k_map_unmap_rq_policer()` calls: **Before:** ```c for (qidx = 0;
qidx < hw->rx_queues; qidx++) cn10k_map_unmap_rq_policer(pfvf, qidx,
hw->matchall_ipolicer, false); ``` **After:** ```c for (qidx = 0; qidx <
hw->rx_queues; qidx++) { rc = cn10k_map_unmap_rq_policer(pfvf, qidx,
hw->matchall_ipolicer, false); if (rc) dev_warn(pfvf->dev, "Failed to
unmap RQ %d's policer (error %d).", qidx, rc); } ``` ### Why This Should
Be Backported 1. **Fixes a Real Bug**: The function was silently
ignoring failures from critical hardware unmapping operations. Based on
my analysis of `otx2_tc.c`, this function can return various error codes
including `-ENOMEM` and mailbox communication failures. 2. **Consistent
Error Handling**: Every other usage of `cn10k_map_unmap_rq_policer()` in
the codebase properly checks return values and logs errors. For example,
in `otx2_tc.c:1216-1221`, the same operation uses: ```c err =
cn10k_map_unmap_rq_policer(nic, flow_node->rq, flow_node->leaf_profile,
false); if (err) netdev_err(nic->netdev, "Unmapping RQ %d & profile %d
failed\n", flow_node->rq, flow_node->leaf_profile); ``` 3. **Meets
Stable Criteria**: This commit: - Fixes a clear bug (missing error
handling) - Is small and contained (only adds error checking) - Has
minimal risk of regression (only adds logging) - Improves system
robustness - Follows the driver's established error handling patterns 4.
**Hardware Resource Management**: The `cn10k_map_unmap_rq_policer()`
function deals with hardware policer resource management. Silent
failures during cleanup could potentially: - Leave hardware in an
inconsistent state - Cause resource leaks - Make debugging network QoS
issues extremely difficult 5. **Alignment with Similar Commits**:
Looking at the provided examples, this commit is very similar to
"Similar Commit #1" and "Similar Commit #4" which both received
"Backport Status: YES". Those commits also added error checking to
`otx2_mbox_get_rsp()` calls that were previously unchecked. 6. **Low
Risk**: The change only adds warning messages and doesn't change the
control flow. Even if the warning message format had issues (which it
doesn't), it wouldn't cause functional problems. 7. **Driver Quality**:
This fix improves the overall quality and debuggability of the OcteonTX2
network driver, which is important for enterprise and datacenter
deployments where these cards are commonly used. The commit represents a
straightforward bug fix that improves error visibility and follows
established patterns in the driver, making it an excellent candidate for
stable tree backporting.

 drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c
index 7417087b6db59..a2807a1e4f4a6 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c
@@ -352,9 +352,12 @@ int cn10k_free_matchall_ipolicer(struct otx2_nic *pfvf)
 	mutex_lock(&pfvf->mbox.lock);
 
 	/* Remove RQ's policer mapping */
-	for (qidx = 0; qidx < hw->rx_queues; qidx++)
-		cn10k_map_unmap_rq_policer(pfvf, qidx,
-					   hw->matchall_ipolicer, false);
+	for (qidx = 0; qidx < hw->rx_queues; qidx++) {
+		rc = cn10k_map_unmap_rq_policer(pfvf, qidx, hw->matchall_ipolicer, false);
+		if (rc)
+			dev_warn(pfvf->dev, "Failed to unmap RQ %d's policer (error %d).",
+				 qidx, rc);
+	}
 
 	rc = cn10k_free_leaf_profile(pfvf, hw->matchall_ipolicer);
 
-- 
2.39.5