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 c3b6e0f60a799..7f6a435ac6806 100644 --- a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c +++ b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c @@ -357,9 +357,12 @@ 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);