On Fri, 26 Jun 2020 18:54:23 -0700 Jeff Kirsher wrote:
> From: Andre Guedes <andre.gue...@intel.com>
>
> The __IGC_PTP_TX_IN_PROGRESS flag indicates we have a pending Tx
> timestamp. In some places, instead of checking that flag, we check
> adapter->ptp_tx_skb. This patch fixes those places to use the flag.
>
> Quick note about igc_ptp_tx_hwtstamp() change: when that function is
> called, adapter->ptp_tx_skb is expected to be valid always so we
> WARN_ON_ONCE() in case it is not.
>
> Quick note about igc_ptp_suspend() change: when suspending, we don't
> really need to check if there is a pending timestamp. We can simply
> clear it unconditionally.
>
> Signed-off-by: Andre Guedes <andre.gue...@intel.com>
> Tested-by: Aaron Brown <aaron.f.br...@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
> ---
> drivers/net/ethernet/intel/igc/igc_ptp.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c
> b/drivers/net/ethernet/intel/igc/igc_ptp.c
> index b1b23c6bf689..e65fdcf966b2 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ptp.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
> @@ -404,9 +404,6 @@ void igc_ptp_tx_hang(struct igc_adapter *adapter)
> bool timeout = time_is_before_jiffies(adapter->ptp_tx_start +
> IGC_PTP_TX_TIMEOUT);
>
> - if (!adapter->ptp_tx_skb)
> - return;
> -
> if (!test_bit(__IGC_PTP_TX_IN_PROGRESS, &adapter->state))
> return;
>
> @@ -435,6 +432,9 @@ static void igc_ptp_tx_hwtstamp(struct igc_adapter
> *adapter)
> struct igc_hw *hw = &adapter->hw;
> u64 regval;
>
> + if (WARN_ON_ONCE(!skb))
> + return;
> +
> regval = rd32(IGC_TXSTMPL);
> regval |= (u64)rd32(IGC_TXSTMPH) << 32;
> igc_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval);
> @@ -466,7 +466,7 @@ static void igc_ptp_tx_work(struct work_struct *work)
> struct igc_hw *hw = &adapter->hw;
> u32 tsynctxctl;
>
> - if (!adapter->ptp_tx_skb)
> + if (!test_bit(__IGC_PTP_TX_IN_PROGRESS, &adapter->state))
> return;
Not that reading ptp_tx_skb is particularly correct here, but I think
it's better. See how they get set:
if (adapter->tstamp_config.tx_type == HWTSTAMP_TX_ON &&
!test_and_set_bit_lock(__IGC_PTP_TX_IN_PROGRESS,
&adapter->state)) {
skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
tx_flags |= IGC_TX_FLAGS_TSTAMP;
adapter->ptp_tx_skb = skb_get(skb);
adapter->ptp_tx_start = jiffies;
bit is set first and other fields after. Since there is no locking here
we may just see the bit but none of the fields set.
> if (time_is_before_jiffies(adapter->ptp_tx_start +
> @@ -588,11 +588,9 @@ void igc_ptp_suspend(struct igc_adapter *adapter)
> return;
>
> cancel_work_sync(&adapter->ptp_tx_work);
> - if (adapter->ptp_tx_skb) {
> - dev_kfree_skb_any(adapter->ptp_tx_skb);
> - adapter->ptp_tx_skb = NULL;
> - clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
> - }
> + dev_kfree_skb_any(adapter->ptp_tx_skb);
> + adapter->ptp_tx_skb = NULL;
> + clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
> }
>
> /**
