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authorJiri Benc2021-09-14 10:54:42 +0200
committerTony Nguyen2021-10-06 09:49:23 -0700
commit857b6c6f665cca9828396d9743faf37fd09e9ac3 (patch)
tree2bc83e58b484af6d5ae830f971dc381dcef009a6
parenta50a0595230d38be15183699f7bbc963bf3d127a (diff)
i40e: fix endless loop under rtnl
The loop in i40e_get_capabilities can never end. The problem is that although i40e_aq_discover_capabilities returns with an error if there's a firmware problem, the returned error is not checked. There is a check for pf->hw.aq.asq_last_status but that value is set to I40E_AQ_RC_OK on most firmware problems. When i40e_aq_discover_capabilities encounters a firmware problem, it will encounter the same problem on its next invocation. As the result, the loop becomes endless. We hit this with I40E_ERR_ADMIN_QUEUE_TIMEOUT but looking at the code, it can happen with a range of other firmware errors. I don't know what the correct behavior should be: whether the firmware should be retried a few times, or whether pf->hw.aq.asq_last_status should be always set to the encountered firmware error (but then it would be pointless and can be just replaced by the i40e_aq_discover_capabilities return value). However, the current behavior with an endless loop under the rtnl mutex(!) is unacceptable and Intel has not submitted a fix, although we explained the bug to them 7 months ago. This may not be the best possible fix but it's better than hanging the whole system on a firmware bug. Fixes: 56a62fc86895 ("i40e: init code and hardware support") Tested-by: Stefan Assmann <sassmann@redhat.com> Signed-off-by: Jiri Benc <jbenc@redhat.com> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Tested-by: Dave Switzer <david.switzer@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_main.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 2f20980dd9a5..b5b984754ec9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -10113,7 +10113,7 @@ static int i40e_get_capabilities(struct i40e_pf *pf,
if (pf->hw.aq.asq_last_status == I40E_AQ_RC_ENOMEM) {
/* retry with a larger buffer */
buf_len = data_size;
- } else if (pf->hw.aq.asq_last_status != I40E_AQ_RC_OK) {
+ } else if (pf->hw.aq.asq_last_status != I40E_AQ_RC_OK || err) {
dev_info(&pf->pdev->dev,
"capability discovery failed, err %s aq_err %s\n",
i40e_stat_str(&pf->hw, err),