On Sat, Aug 12, 2017 at 4:08 AM, Jeff Kirsher
<jeffrey.t.kirs...@intel.com> wrote:
> From: Sudheer Mogilappagari <sudheer.mogilappag...@intel.com>
>
> 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.mogilappag...@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
> ---
> drivers/net/ethernet/intel/i40e/i40e_nvm.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_nvm.c
> b/drivers/net/ethernet/intel/i40e/i40e_nvm.c
> index 6fdecd70dcbc..2cf7db2dc7cd 100644
> --- 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 i40e_hw *hw,
> 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 i40e_hw *hw,
> *perrno = -ESRCH;
> break;
> }
Perhaps I missed a patch somewhere, but I think there is still a
return statement in the middle of this switch() (INIT_WAIT and
WRITE_WAIT) that means you can leave the mutex locked. I thought I
had seen a newer version of this patch that had this fixed
sln
> + mutex_unlock(&hw->aq.arq_mutex);
> return status;
> }
>
> --
> 2.14.0
>
--
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