ptp_clock: future-proofing drivers against PTP subsystem becoming optional
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 <nico@linaro.org>
Reviewed-by: Eugenia Emantayev <eugenia@mellanox.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/intel/e1000e/ptp.c b/drivers/net/ethernet/intel/e1000e/ptp.c
index 2e1b17a..ad03763 100644
--- a/drivers/net/ethernet/intel/e1000e/ptp.c
+++ b/drivers/net/ethernet/intel/e1000e/ptp.c
@@ -334,7 +334,7 @@
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 ed39cba..f1fecea 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
@@ -669,7 +669,7 @@
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 66dfa20..1dd14e1 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -1159,7 +1159,7 @@
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 e5431bf..a922776 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
@@ -1254,7 +1254,7 @@
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 1494997..08fc5fc 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
@@ -298,7 +298,7 @@
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 847a8f3..13dc388 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 @@
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 dd204d9..77a5364 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -1269,13 +1269,13 @@
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 170a18b..6e3b829 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
@@ -187,7 +187,7 @@
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 6b15e16..5ad54fc 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -127,6 +127,11 @@
*
* @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,