diff mbox series

[1/2] net: wwan: iosm: Let PCI core handle PCI power transition

Message ID 20211224081914.345292-1-kai.heng.feng@canonical.com
State New
Headers show
Series [1/2] net: wwan: iosm: Let PCI core handle PCI power transition | expand

Commit Message

Kai-Heng Feng Dec. 24, 2021, 8:19 a.m. UTC
pci_pm_suspend_noirq() and pci_pm_resume_noirq() already handle power
transition for system-wide suspend and resume, so it's not necessary to
do it in the driver.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/net/wwan/iosm/iosm_ipc_pcie.c | 49 ++-------------------------
 1 file changed, 2 insertions(+), 47 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Dec. 27, 2021, 12:30 p.m. UTC | #1
Hello:

This series was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Fri, 24 Dec 2021 16:19:13 +0800 you wrote:
> pci_pm_suspend_noirq() and pci_pm_resume_noirq() already handle power
> transition for system-wide suspend and resume, so it's not necessary to
> do it in the driver.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
>  drivers/net/wwan/iosm/iosm_ipc_pcie.c | 49 ++-------------------------
>  1 file changed, 2 insertions(+), 47 deletions(-)

Here is the summary with links:
  - [1/2] net: wwan: iosm: Let PCI core handle PCI power transition
    https://git.kernel.org/netdev/net-next/c/8f58e29ed7fc
  - [2/2] net: wwan: iosm: Keep device at D0 for s2idle case
    https://git.kernel.org/netdev/net-next/c/f4dd5174e273

You are awesome, thank you!
Bjorn Helgaas Dec. 29, 2021, 8:12 p.m. UTC | #2
[+cc Rafael, in case you have insight about the PCI_D0 question below;
Vaibhav, since this is related to your generic PM conversions]

On Fri, Dec 24, 2021 at 04:19:13PM +0800, Kai-Heng Feng wrote:
> pci_pm_suspend_noirq() and pci_pm_resume_noirq() already handle power
> transition for system-wide suspend and resume, so it's not necessary to
> do it in the driver.

I see DaveM has already applied this, but it looks good to me, thanks
for doing this!

One minor question below...

> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
>  drivers/net/wwan/iosm/iosm_ipc_pcie.c | 49 ++-------------------------
>  1 file changed, 2 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.c b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
> index 2fe88b8be3481..d73894e2a84ed 100644
> --- a/drivers/net/wwan/iosm/iosm_ipc_pcie.c
> +++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
> @@ -363,67 +363,22 @@ static int __maybe_unused ipc_pcie_resume_s2idle(struct iosm_pcie *ipc_pcie)
>  
>  int __maybe_unused ipc_pcie_suspend(struct iosm_pcie *ipc_pcie)
>  {
> -	struct pci_dev *pdev;
> -	int ret;
> -
> -	pdev = ipc_pcie->pci;
> -
> -	/* Execute D3 one time. */
> -	if (pdev->current_state != PCI_D0) {
> -		dev_dbg(ipc_pcie->dev, "done for PM=%d", pdev->current_state);
> -		return 0;
> -	}

I don't understand the intent of this early exit, and it's not obvious
to me that pci_pm_suspend_noirq() bails out early when
(pdev->current_state != PCI_D0).

>  	/* The HAL shall ask the shared memory layer whether D3 is allowed. */
>  	ipc_imem_pm_suspend(ipc_pcie->imem);
>  
> -	/* Save the PCI configuration space of a device before suspending. */
> -	ret = pci_save_state(pdev);
> -
> -	if (ret) {
> -		dev_err(ipc_pcie->dev, "pci_save_state error=%d", ret);
> -		return ret;
> -	}
> -
> -	/* Set the power state of a PCI device.
> -	 * Transition a device to a new power state, using the device's PCI PM
> -	 * registers.
> -	 */
> -	ret = pci_set_power_state(pdev, PCI_D3cold);
> -
> -	if (ret) {
> -		dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
> -		return ret;
> -	}
> -
>  	dev_dbg(ipc_pcie->dev, "SUSPEND done");
> -	return ret;
> +	return 0;
>  }
>  
>  int __maybe_unused ipc_pcie_resume(struct iosm_pcie *ipc_pcie)
>  {
> -	int ret;
> -
> -	/* Set the power state of a PCI device.
> -	 * Transition a device to a new power state, using the device's PCI PM
> -	 * registers.
> -	 */
> -	ret = pci_set_power_state(ipc_pcie->pci, PCI_D0);
> -
> -	if (ret) {
> -		dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
> -		return ret;
> -	}
> -
> -	pci_restore_state(ipc_pcie->pci);
> -
>  	/* The HAL shall inform the shared memory layer that the device is
>  	 * active.
>  	 */
>  	ipc_imem_pm_resume(ipc_pcie->imem);
>  
>  	dev_dbg(ipc_pcie->dev, "RESUME done");
> -	return ret;
> +	return 0;
>  }
>  
>  static int __maybe_unused ipc_pcie_suspend_cb(struct device *dev)
> -- 
> 2.33.1
>
Kai-Heng Feng Dec. 30, 2021, 12:57 a.m. UTC | #3
On Thu, Dec 30, 2021 at 4:12 AM Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> [+cc Rafael, in case you have insight about the PCI_D0 question below;
> Vaibhav, since this is related to your generic PM conversions]
>
> On Fri, Dec 24, 2021 at 04:19:13PM +0800, Kai-Heng Feng wrote:
> > pci_pm_suspend_noirq() and pci_pm_resume_noirq() already handle power
> > transition for system-wide suspend and resume, so it's not necessary to
> > do it in the driver.
>
> I see DaveM has already applied this, but it looks good to me, thanks
> for doing this!
>
> One minor question below...
>
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > ---
> >  drivers/net/wwan/iosm/iosm_ipc_pcie.c | 49 ++-------------------------
> >  1 file changed, 2 insertions(+), 47 deletions(-)
> >
> > diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.c b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
> > index 2fe88b8be3481..d73894e2a84ed 100644
> > --- a/drivers/net/wwan/iosm/iosm_ipc_pcie.c
> > +++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
> > @@ -363,67 +363,22 @@ static int __maybe_unused ipc_pcie_resume_s2idle(struct iosm_pcie *ipc_pcie)
> >
> >  int __maybe_unused ipc_pcie_suspend(struct iosm_pcie *ipc_pcie)
> >  {
> > -     struct pci_dev *pdev;
> > -     int ret;
> > -
> > -     pdev = ipc_pcie->pci;
> > -
> > -     /* Execute D3 one time. */
> > -     if (pdev->current_state != PCI_D0) {
> > -             dev_dbg(ipc_pcie->dev, "done for PM=%d", pdev->current_state);
> > -             return 0;
> > -     }
>
> I don't understand the intent of this early exit, and it's not obvious
> to me that pci_pm_suspend_noirq() bails out early when
> (pdev->current_state != PCI_D0).

Yes, I think this can be removed too. Please let me send v2.

Kai-Heng

>
> >       /* The HAL shall ask the shared memory layer whether D3 is allowed. */
> >       ipc_imem_pm_suspend(ipc_pcie->imem);
> >
> > -     /* Save the PCI configuration space of a device before suspending. */
> > -     ret = pci_save_state(pdev);
> > -
> > -     if (ret) {
> > -             dev_err(ipc_pcie->dev, "pci_save_state error=%d", ret);
> > -             return ret;
> > -     }
> > -
> > -     /* Set the power state of a PCI device.
> > -      * Transition a device to a new power state, using the device's PCI PM
> > -      * registers.
> > -      */
> > -     ret = pci_set_power_state(pdev, PCI_D3cold);
> > -
> > -     if (ret) {
> > -             dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
> > -             return ret;
> > -     }
> > -
> >       dev_dbg(ipc_pcie->dev, "SUSPEND done");
> > -     return ret;
> > +     return 0;
> >  }
> >
> >  int __maybe_unused ipc_pcie_resume(struct iosm_pcie *ipc_pcie)
> >  {
> > -     int ret;
> > -
> > -     /* Set the power state of a PCI device.
> > -      * Transition a device to a new power state, using the device's PCI PM
> > -      * registers.
> > -      */
> > -     ret = pci_set_power_state(ipc_pcie->pci, PCI_D0);
> > -
> > -     if (ret) {
> > -             dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
> > -             return ret;
> > -     }
> > -
> > -     pci_restore_state(ipc_pcie->pci);
> > -
> >       /* The HAL shall inform the shared memory layer that the device is
> >        * active.
> >        */
> >       ipc_imem_pm_resume(ipc_pcie->imem);
> >
> >       dev_dbg(ipc_pcie->dev, "RESUME done");
> > -     return ret;
> > +     return 0;
> >  }
> >
> >  static int __maybe_unused ipc_pcie_suspend_cb(struct device *dev)
> > --
> > 2.33.1
> >
diff mbox series

Patch

diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.c b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
index 2fe88b8be3481..d73894e2a84ed 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_pcie.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
@@ -363,67 +363,22 @@  static int __maybe_unused ipc_pcie_resume_s2idle(struct iosm_pcie *ipc_pcie)
 
 int __maybe_unused ipc_pcie_suspend(struct iosm_pcie *ipc_pcie)
 {
-	struct pci_dev *pdev;
-	int ret;
-
-	pdev = ipc_pcie->pci;
-
-	/* Execute D3 one time. */
-	if (pdev->current_state != PCI_D0) {
-		dev_dbg(ipc_pcie->dev, "done for PM=%d", pdev->current_state);
-		return 0;
-	}
-
 	/* The HAL shall ask the shared memory layer whether D3 is allowed. */
 	ipc_imem_pm_suspend(ipc_pcie->imem);
 
-	/* Save the PCI configuration space of a device before suspending. */
-	ret = pci_save_state(pdev);
-
-	if (ret) {
-		dev_err(ipc_pcie->dev, "pci_save_state error=%d", ret);
-		return ret;
-	}
-
-	/* Set the power state of a PCI device.
-	 * Transition a device to a new power state, using the device's PCI PM
-	 * registers.
-	 */
-	ret = pci_set_power_state(pdev, PCI_D3cold);
-
-	if (ret) {
-		dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
-		return ret;
-	}
-
 	dev_dbg(ipc_pcie->dev, "SUSPEND done");
-	return ret;
+	return 0;
 }
 
 int __maybe_unused ipc_pcie_resume(struct iosm_pcie *ipc_pcie)
 {
-	int ret;
-
-	/* Set the power state of a PCI device.
-	 * Transition a device to a new power state, using the device's PCI PM
-	 * registers.
-	 */
-	ret = pci_set_power_state(ipc_pcie->pci, PCI_D0);
-
-	if (ret) {
-		dev_err(ipc_pcie->dev, "pci_set_power_state error=%d", ret);
-		return ret;
-	}
-
-	pci_restore_state(ipc_pcie->pci);
-
 	/* The HAL shall inform the shared memory layer that the device is
 	 * active.
 	 */
 	ipc_imem_pm_resume(ipc_pcie->imem);
 
 	dev_dbg(ipc_pcie->dev, "RESUME done");
-	return ret;
+	return 0;
 }
 
 static int __maybe_unused ipc_pcie_suspend_cb(struct device *dev)