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

Myeonghun Pak posted 1 patch 1 week, 3 days ago
drivers/net/ethernet/intel/idpf/idpf_main.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
[PATCH v2] idpf: disable PCIe PTM on probe failure and removal
Posted by Myeonghun Pak 1 week, 3 days ago
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
Re: [PATCH v2] idpf: disable PCIe PTM on probe failure and removal
Posted by Tony Nguyen 1 week ago

On 7/15/2026 12:43 AM, Myeonghun Pak wrote:
> 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);

Sashiko says:

If pci_enable_ptm() failed earlier during idpf_probe() because it was
unsupported by the bus or controller, does this unconditional call to
pci_disable_ptm() corrupt the upstream PTM enable counts?
Looking at pci_disable_ptm(), it does not check if the local device was
successfully enabled. It climbs the PCIe tree and erroneously decrements
atomic counters like ptm_enable_cnt on parent switches.
Could this eventually break PTM for other downstream devices sharing the 
same
switch if a parent's count is incorrectly decremented to -1?

>   	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);

Like the issue in idpf_remove(), does this error path unconditionally 
disable
PTM even if the earlier enable attempt failed?
If a subsequent probe step fails (such as dma_set_mask_and_coherent or
workqueue allocation), this path is taken regardless of whether
pci_enable_ptm() succeeded.
Would it make sense to track the PTM state in the adapter struct, and only
call pci_disable_ptm() when it was successfully enabled?

>   err_free:
>   	kfree(adapter);
>   	return err;
Re: [PATCH v2] idpf: disable PCIe PTM on probe failure and removal
Posted by Myeonghun Pak 5 days, 3 hours ago
You are right, thanks for catching this. I missed that pci_disable_ptm()
now decrements dev->ptm_enable_cnt unconditionally and recurses upstream,
so calling it after a failed enable would corrupt the counts of parents
shared with other endpoints.

v3 will guard both call sites with pcie_ptm_enabled(), which idpf already
uses in idpf_ptp_set_caps(), so no new adapter field is needed. v2 also
needs a rebase since pci_enable_ptm() lost its granularity argument.

Thanks,
Myeonghun

2026년 7월 18일 (토) 오전 5:21, Tony Nguyen <anthony.l.nguyen@intel.com>님이 작성:
>
>
>
> On 7/15/2026 12:43 AM, Myeonghun Pak wrote:
> > 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);
>
> Sashiko says:
>
> If pci_enable_ptm() failed earlier during idpf_probe() because it was
> unsupported by the bus or controller, does this unconditional call to
> pci_disable_ptm() corrupt the upstream PTM enable counts?
> Looking at pci_disable_ptm(), it does not check if the local device was
> successfully enabled. It climbs the PCIe tree and erroneously decrements
> atomic counters like ptm_enable_cnt on parent switches.
> Could this eventually break PTM for other downstream devices sharing the
> same
> switch if a parent's count is incorrectly decremented to -1?
>
> >       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);
>
> Like the issue in idpf_remove(), does this error path unconditionally
> disable
> PTM even if the earlier enable attempt failed?
> If a subsequent probe step fails (such as dma_set_mask_and_coherent or
> workqueue allocation), this path is taken regardless of whether
> pci_enable_ptm() succeeded.
> Would it make sense to track the PTM state in the adapter struct, and only
> call pci_disable_ptm() when it was successfully enabled?
>
> >   err_free:
> >       kfree(adapter);
> >       return err;
>
Re: [PATCH v2] idpf: disable PCIe PTM on probe failure and removal
Posted by Mina Almasry 1 week, 2 days ago
On Wed, Jul 15, 2026 at 12:44 AM Myeonghun Pak <mhun512@gmail.com> wrote:
>
> 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>

Reviewed-by: Mina Almasry <almasrymina@google.com>


-- 
Thanks,
Mina
RE: [Intel-wired-lan] [PATCH v2] idpf: disable PCIe PTM on probe failure and removal
Posted by Loktionov, Aleksandr 1 week, 3 days ago

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Myeonghun Pak
> Sent: Wednesday, July 15, 2026 9:44 AM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; intel-wired-
> lan@lists.osuosl.org
> Cc: Olech, Milena <milena.olech@intel.com>; Tantilov, Emil S
> <emil.s.tantilov@intel.com>; Andrew Lunn <andrew+netdev@lunn.ch>;
> David S . Miller <davem@davemloft.net>; Eric Dumazet
> <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni
> <pabeni@redhat.com>; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; Myeonghun Pak <mhun512@gmail.com>; Ijae Kim
> <ae878000@gmail.com>
> Subject: [Intel-wired-lan] [PATCH v2] idpf: disable PCIe PTM on probe
> failure and removal
> 
> 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

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>