[PATCH net 1/1] i40e: Fix erroneous adapter reinitialization during recovery process

[PATCH net 1/1] i40e: Fix erroneous adapter reinitialization during recovery process

[Tony Nguyen]

From: Dawid Lukwinski <dawid.lukwinski@intel.com>

Fix an issue when driver incorrectly detects state
of recovery process and erroneously reinitializes interrupts,
which results in a kernel error and call trace message.

The issue was caused by a combination of two factors:
1. Assuming the EMP reset issued after completing
firmware recovery means the whole recovery process is complete.
2. Erroneous reinitialization of interrupt vector after detecting
the above mentioned EMP reset.

Fixes (1) by changing how recovery state change is detected
and (2) by adjusting the conditional expression to ensure using proper
interrupt reinitialization method, depending on the situation.

Fixes: 4ff0ee1af016 ("i40e: Introduce recovery mode support")
Signed-off-by: Dawid Lukwinski <dawid.lukwinski@intel.com>
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index aa786fd55951..7f1a0d90dc51 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -10650,7 +10650,7 @@ static int i40e_reset(struct i40e_pf *pf)
  **/
 static void i40e_rebuild(struct i40e_pf *pf, bool reinit, bool lock_acquired)
 {
-	int old_recovery_mode_bit = test_bit(__I40E_RECOVERY_MODE, pf->state);
+	const bool is_recovery_mode_reported = i40e_check_recovery_mode(pf);
 	struct i40e_vsi *vsi = pf->vsi[pf->lan_vsi];
 	struct i40e_hw *hw = &pf->hw;
 	i40e_status ret;
@@ -10658,13 +10658,11 @@ static void i40e_rebuild(struct i40e_pf *pf, bool reinit, bool lock_acquired)
 	int v;
 
 	if (test_bit(__I40E_EMP_RESET_INTR_RECEIVED, pf->state) &&
-	    i40e_check_recovery_mode(pf)) {
+	    is_recovery_mode_reported)
 		i40e_set_ethtool_ops(pf->vsi[pf->lan_vsi]->netdev);
-	}
 
 	if (test_bit(__I40E_DOWN, pf->state) &&
-	    !test_bit(__I40E_RECOVERY_MODE, pf->state) &&
-	    !old_recovery_mode_bit)
+	    !test_bit(__I40E_RECOVERY_MODE, pf->state))
 		goto clear_recovery;
 	dev_dbg(&pf->pdev->dev, "Rebuilding internal switch\n");
 
@@ -10691,13 +10689,12 @@ static void i40e_rebuild(struct i40e_pf *pf, bool reinit, bool lock_acquired)
 	 * accordingly with regard to resources initialization
 	 * and deinitialization
 	 */
-	if (test_bit(__I40E_RECOVERY_MODE, pf->state) ||
-	    old_recovery_mode_bit) {
+	if (test_bit(__I40E_RECOVERY_MODE, pf->state)) {
 		if (i40e_get_capabilities(pf,
 					  i40e_aqc_opc_list_func_capabilities))
 			goto end_unlock;
 
-		if (test_bit(__I40E_RECOVERY_MODE, pf->state)) {
+		if (is_recovery_mode_reported) {
 			/* we're staying in recovery mode so we'll reinitialize
 			 * misc vector here
 			 */
-- 
2.35.1

Re: [PATCH net 1/1] i40e: Fix erroneous adapter reinitialization during recovery process

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 15 Jul 2022 14:45:41 -0700 you wrote:
> From: Dawid Lukwinski <dawid.lukwinski@intel.com>
> 
> Fix an issue when driver incorrectly detects state
> of recovery process and erroneously reinitializes interrupts,
> which results in a kernel error and call trace message.
> 
> The issue was caused by a combination of two factors:
> 1. Assuming the EMP reset issued after completing
> firmware recovery means the whole recovery process is complete.
> 2. Erroneous reinitialization of interrupt vector after detecting
> the above mentioned EMP reset.
> 
> [...]

Here is the summary with links:
  - [net,1/1] i40e: Fix erroneous adapter reinitialization during recovery process
    https://git.kernel.org/netdev/net/c/f838a6336981

You are awesome, thank you!
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