From: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
Date: Wed, 12 Jul 2017 05:46:07 -0400
Subject: i40e: synchronize nvmupdate command and adminq subtask
Patch-mainline: v4.14-rc1
Git-commit: 2bf01935ec5362aee6ff9ffc2476043af321aa42
References: bsc#1056658 FATE#322188 bsc#1056662 FATE#322186
During NVM update, state machine gets into unrecoverable state because
i40e_clean_adminq_subtask can get scheduled after the admin queue
command but before other state variables are updated. This causes
incorrect input to i40e_nvmupd_check_wait_event and state transitions
don't happen.
This issue existed before but surfaced after commit 373149fc99a0
("i40e: Decrease the scope of rtnl lock")
This fix adds locking around admin queue command and update of
state variables so that adminq_subtask will have accurate information
whenever it gets scheduled.
Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Benjamin Poirier <bpoirier@suse.com>
---
drivers/net/ethernet/intel/i40e/i40e_nvm.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/net/ethernet/intel/i40e/i40e_nvm.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_nvm.c
@@ -753,6 +753,11 @@ i40e_status i40e_nvmupd_command(struct i
hw->nvmupd_state = I40E_NVMUPD_STATE_INIT;
}
+ /* Acquire lock to prevent race condition where adminq_task
+ * can execute after i40e_nvmupd_nvm_read/write but before state
+ * variables (nvm_wait_opcode, nvm_release_on_done) are updated
+ */
+ mutex_lock(&hw->aq.arq_mutex);
switch (hw->nvmupd_state) {
case I40E_NVMUPD_STATE_INIT:
status = i40e_nvmupd_state_init(hw, cmd, bytes, perrno);
@@ -788,6 +793,7 @@ i40e_status i40e_nvmupd_command(struct i
*perrno = -ESRCH;
break;
}
+ mutex_unlock(&hw->aq.arq_mutex);
return status;
}