[PATCH v2] idpf: disable PCIe PTM on probe failure and removal

[Myeonghun Pak <mhun512@gmail.com>]

idpf_probe() enables PCIe Precision Time Measurement with
pci_enable_ptm(pdev, NULL), which programs the PTM control bits and sets
pdev->ptm_enabled when the bus/controller supports it.

If a later probe step fails, the error path releases the allocated
workqueues and adapter memory without disabling PTM.  The remove path has
the same imbalance when a successfully probed device is detached.  In
both cases, the PCI core's software PTM state and the device's PTM control
bits remain set with no bound driver.

Add pci_disable_ptm() to the common probe unwind after the PTM enable and
to idpf_remove().  pci_disable_ptm() is a no-op when PTM was not enabled,
so the non-fatal pci_enable_ptm() failure remains safe.
pcim_enable_device() only arranges for pci_disable_device() and does not
undo the PTM enable.

Fixes: 8d5e12c5921c ("idpf: add initial PTP support")
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
Changes in v2:
- Disable PTM in the probe error path, as requested by Emil Tantilov.

 drivers/net/ethernet/intel/idpf/idpf_main.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_main.c b/drivers/net/ethernet/intel/idpf/idpf_main.c
index 0dd741dcfc..f08ce13c20 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_main.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_main.c
@@ -159,6 +159,7 @@ static void idpf_remove(struct pci_dev *pdev)
 	mutex_destroy(&adapter->queue_lock);
 	mutex_destroy(&adapter->vc_buf_lock);
 
+	pci_disable_ptm(pdev);
 	pci_set_drvdata(pdev, NULL);
 	kfree(adapter);
 }
@@ -266,7 +267,7 @@ static int idpf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (err) {
 		pci_err(pdev, "DMA configuration failed: %pe\n", ERR_PTR(err));
 
-		goto err_free;
+		goto err_disable_ptm;
 	}
 
 	pci_set_master(pdev);
@@ -279,7 +280,7 @@ static int idpf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (!adapter->init_wq) {
 		dev_err(dev, "Failed to allocate init workqueue\n");
 		err = -ENOMEM;
-		goto err_free;
+		goto err_disable_ptm;
 	}
 
 	adapter->serv_wq = alloc_workqueue("%s-%s-service",
@@ -366,6 +367,8 @@ err_mbx_wq_alloc:
 	destroy_workqueue(adapter->serv_wq);
 err_serv_wq_alloc:
 	destroy_workqueue(adapter->init_wq);
+err_disable_ptm:
+	pci_disable_ptm(pdev);
 err_free:
 	kfree(adapter);
 	return err;
-- 
2.47.1