diff mbox series

[v2,2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled

Message ID 20220714231609.3962051-2-rajvi.jingar@linux.intel.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series [v2,1/2] PCI/PM: refactor pci_pm_suspend_noirq() | expand

Commit Message

rajvi.jingar July 14, 2022, 11:16 p.m. UTC
pci_dev->ptm_enabled needs to be maintained to reflect the current PTM
state of the device. In pci_ptm_disable(), clear ptm_enabled from
'struct pci_dev' on disabling PTM state for the device.
In pci_restore_ptm_state(), set dev->ptm_enabled based on the restored
PTM state of the device.

Also, perform ptm_enabled check in pci_ptm_disable() to avoid config
space access in case if PTM is already disabled for the device.

Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
---
 v1->v2:
   - add ptm_enabled check in pci_ptm_disable().
   - set the dev->ptm_enabled value in pci_restore_ptm_state().
---
 drivers/pci/pcie/ptm.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Rafael J. Wysocki July 15, 2022, 11:46 a.m. UTC | #1
On Fri, Jul 15, 2022 at 1:16 AM Rajvi Jingar
<rajvi.jingar@linux.intel.com> wrote:
>
> pci_dev->ptm_enabled needs to be maintained to reflect the current PTM
> state of the device. In pci_ptm_disable(), clear ptm_enabled from
> 'struct pci_dev' on disabling PTM state for the device.
> In pci_restore_ptm_state(), set dev->ptm_enabled based on the restored
> PTM state of the device.
>
> Also, perform ptm_enabled check in pci_ptm_disable() to avoid config
> space access in case if PTM is already disabled for the device.
>
> Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> ---
>  v1->v2:
>    - add ptm_enabled check in pci_ptm_disable().
>    - set the dev->ptm_enabled value in pci_restore_ptm_state().
> ---
>  drivers/pci/pcie/ptm.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
> index 368a254e3124..8dc7d2285a0d 100644
> --- a/drivers/pci/pcie/ptm.c
> +++ b/drivers/pci/pcie/ptm.c
> @@ -34,6 +34,9 @@ void pci_disable_ptm(struct pci_dev *dev)
>         int ptm;
>         u16 ctrl;
>
> +       if (!dev->ptm_enabled)
> +               return;
> +
>         if (!pci_is_pcie(dev))
>                 return;

After the check you've added this doesn't need to be checked any more,
because ptm_enabled will not be set if pci_is_pcie(dev) is not true
AFAICS.

Otherwise the patch looks good to me, so with the above addressed,
please feel free to add

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

to it.

Thanks!

>
> @@ -44,6 +47,7 @@ void pci_disable_ptm(struct pci_dev *dev)
>         pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl);
>         ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT);
>         pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl);
> +       dev->ptm_enabled = 0;
>  }
>
>  void pci_save_ptm_state(struct pci_dev *dev)
> @@ -83,6 +87,7 @@ void pci_restore_ptm_state(struct pci_dev *dev)
>
>         cap = (u16 *)&save_state->cap.data[0];
>         pci_write_config_word(dev, ptm + PCI_PTM_CTRL, *cap);
> +       dev->ptm_enabled = !!(*cap & PCI_PTM_CTRL_ENABLE);
>  }
>
>  void pci_ptm_init(struct pci_dev *dev)
> --
> 2.25.1
>
diff mbox series

Patch

diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index 368a254e3124..8dc7d2285a0d 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -34,6 +34,9 @@  void pci_disable_ptm(struct pci_dev *dev)
 	int ptm;
 	u16 ctrl;
 
+	if (!dev->ptm_enabled)
+		return;
+
 	if (!pci_is_pcie(dev))
 		return;
 
@@ -44,6 +47,7 @@  void pci_disable_ptm(struct pci_dev *dev)
 	pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl);
 	ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT);
 	pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl);
+	dev->ptm_enabled = 0;
 }
 
 void pci_save_ptm_state(struct pci_dev *dev)
@@ -83,6 +87,7 @@  void pci_restore_ptm_state(struct pci_dev *dev)
 
 	cap = (u16 *)&save_state->cap.data[0];
 	pci_write_config_word(dev, ptm + PCI_PTM_CTRL, *cap);
+	dev->ptm_enabled = !!(*cap & PCI_PTM_CTRL_ENABLE);
 }
 
 void pci_ptm_init(struct pci_dev *dev)