[PATCH] ptp_clock: future-proofing drivers against PTP subsystem becoming optional
From: Nicolas Pitre <hidden>
Date: 2016-09-20 23:26:03
Drivers must be ready to accept NULL from ptp_clock_register() if the PTP clock subsystem is configured out. This patch documents that and ensures that all drivers cope well with a NULL return. Signed-off-by: Nicolas Pitre <redacted> Reviewed-by: Eugenia Emantayev <redacted> --- Let's have the basics merged now and work out the actual Kconfig issue separately. Richard, if you agree with this patch, I think this could go via the netdev tree.
diff --git a/drivers/net/ethernet/intel/e1000e/ptp.c b/drivers/net/ethernet/intel/e1000e/ptp.c
index 2e1b17ad52..ad03763e00 100644
--- a/drivers/net/ethernet/intel/e1000e/ptp.c
+++ b/drivers/net/ethernet/intel/e1000e/ptp.c@@ -334,7 +334,7 @@ void e1000e_ptp_init(struct e1000_adapter *adapter) if (IS_ERR(adapter->ptp_clock)) { adapter->ptp_clock = NULL; e_err("ptp_clock_register failed\n"); - } else { + } else if (adapter->ptp_clock) { e_info("registered PHC clock\n"); } }
diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
index ed39cbad24..f1feceab75 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c@@ -669,7 +669,7 @@ void i40e_ptp_init(struct i40e_pf *pf) pf->ptp_clock = NULL; dev_err(&pf->pdev->dev, "%s: ptp_clock_register failed\n", __func__); - } else { + } else if (pf->ptp_clock) { struct timespec64 ts; u32 regval;
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index 336c103ae3..7531892b08 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c@@ -1159,7 +1159,7 @@ void igb_ptp_init(struct igb_adapter *adapter) if (IS_ERR(adapter->ptp_clock)) { adapter->ptp_clock = NULL; dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n"); - } else { + } else if (adapter->ptp_clock) { dev_info(&adapter->pdev->dev, "added PHC on %s\n", adapter->netdev->name); adapter->ptp_flags |= IGB_PTP_ENABLED;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
index e5431bfe33..a92277683a 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c@@ -1254,7 +1254,7 @@ static long ixgbe_ptp_create_clock(struct ixgbe_adapter *adapter) adapter->ptp_clock = NULL; e_dev_err("ptp_clock_register failed\n"); return err; - } else + } else if (adapter->ptp_clock) e_dev_info("registered PHC device on %s\n", netdev->name); /* set default timestamp mode to disabled here. We do this in
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
index 1494997c4f..08fc5fc56d 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c@@ -298,7 +298,7 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) if (IS_ERR(mdev->ptp_clock)) { mdev->ptp_clock = NULL; mlx4_err(mdev, "ptp_clock_register failed\n"); - } else { + } else if (mdev->ptp_clock) { mlx4_info(mdev, "registered PHC clock\n"); }
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c b/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
index 847a8f3ac2..13dc388667 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c@@ -273,7 +273,7 @@ void mlx5e_timestamp_init(struct mlx5e_priv *priv) tstamp->ptp = ptp_clock_register(&tstamp->ptp_info, &priv->mdev->pdev->dev); - if (IS_ERR_OR_NULL(tstamp->ptp)) { + if (IS_ERR(tstamp->ptp)) { mlx5_core_warn(priv->mdev, "ptp_clock_register failed %ld\n", PTR_ERR(tstamp->ptp)); tstamp->ptp = NULL;
diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index c771e0af4e..f105a170b4 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c@@ -1269,13 +1269,13 @@ int efx_ptp_probe(struct efx_nic *efx, struct efx_channel *channel) if (IS_ERR(ptp->phc_clock)) { rc = PTR_ERR(ptp->phc_clock); goto fail3; - } - - INIT_WORK(&ptp->pps_work, efx_ptp_pps_worker); - ptp->pps_workwq = create_singlethread_workqueue("sfc_pps"); - if (!ptp->pps_workwq) { - rc = -ENOMEM; - goto fail4; + } else if (ptp->phc_clock) { + INIT_WORK(&ptp->pps_work, efx_ptp_pps_worker); + ptp->pps_workwq = create_singlethread_workqueue("sfc_pps"); + if (!ptp->pps_workwq) { + rc = -ENOMEM; + goto fail4; + } } } ptp->nic_ts_enabled = false;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
index 170a18b612..6e3b82972c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c@@ -187,7 +187,7 @@ int stmmac_ptp_register(struct stmmac_priv *priv) if (IS_ERR(priv->ptp_clock)) { priv->ptp_clock = NULL; pr_err("ptp_clock_register() failed on %s\n", priv->dev->name); - } else + } else if (priv->ptp_clock) pr_debug("Added PTP HW clock successfully on %s\n", priv->dev->name);
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index 6b15e16814..5ad54fc66c 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h@@ -127,6 +127,11 @@ struct ptp_clock; * * @info: Structure describing the new clock. * @parent: Pointer to the parent device of the new clock. + * + * Returns a valid pointer on success or PTR_ERR on failure. If PHC + * support is missing at the configuration level, this function + * returns NULL, and drivers are expected to gracefully handle that + * case separately. */ extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,