| From 0750fe0f25232634e6bb651b76959ae2068adb8b Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 14 Sep 2021 10:54:42 +0200 |
| Subject: i40e: fix endless loop under rtnl |
| |
| From: Jiri Benc <jbenc@redhat.com> |
| |
| [ Upstream commit 857b6c6f665cca9828396d9743faf37fd09e9ac3 ] |
| |
| 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> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/ethernet/intel/i40e/i40e_main.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c |
| index 246734be5177..8f7d3af75ed6 100644 |
| --- a/drivers/net/ethernet/intel/i40e/i40e_main.c |
| +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c |
| @@ -9068,7 +9068,7 @@ 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), |
| -- |
| 2.33.0 |
| |