From: Jiri Benc <jbenc@redhat.com> stable inclusion from stable-5.10.73 commit 2dc768a98c9b83f33a2bc98a275bf4b352d946f1 bugzilla: 182983 https://gitee.com/openeuler/kernel/issues/I4I3M0 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- 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 bc648ce0743c..0a1eea0846e6 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -9662,7 +9662,7 @@ 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), -- 2.20.1