ACK/cmnt: [SRU][Artful][Bionic][Cosmic][PATCH 1/1] UBUNTU: SAUCE: PCI / PM: Check device_may_wakeup() in pci_enable_wake()

[Kleber Souza]

On 05/11/18 20:41, Joseph Salisbury wrote:
> From: "Rafael J. Wysocki" <rafael.j.wysocki at intel.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1765646

The correct BugLink is http://bugs.launchpad.net/bugs/1745646

This can be fixed when applying the patch.

> 
> Commit 0847684cfc5f0 (PCI / PM: Simplify device wakeup settings code)
> went too far and dropped the device_may_wakeup() check from
> pci_enable_wake() which causes wakeup to be enabled during system
> suspend, hibernation or shutdown for some PCI devices that are not
> allowed by user space to wake up the system from sleep (or power off).
> 
> As a result of this excessive power is drawn by some of the affected
> systems while in sleep states or off.
> 
> Restore the device_may_wakeup() check in pci_enable_wake(), but make
> sure that the PCI bus type's runtime suspend callback will not call
> device_may_wakeup() which is about system wakeup from sleep and not
> about device wakeup from runtime suspend.
> 
> Fixes: 0847684cfc5f0 (PCI / PM: Simplify device wakeup settings code)
> Reported-by: Joseph Salisbury <joseph.salisbury at canonical.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
> Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>

The patch has landed upstream as cfcadfaad7251d8b640713724b388164d75465b2.

We can fix the subject to remove the "UBUNTU: SAUCE:" part and fix the
SOB block when applying the patch.

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>


> ---
>  drivers/pci/pci.c | 29 +++++++++++++++++++++++------
>  1 file changed, 23 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 8eac876..b1faa84 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -1893,7 +1893,7 @@ void pci_pme_active(struct pci_dev *dev, bool enable)
>  EXPORT_SYMBOL(pci_pme_active);
>  
>  /**
> - * pci_enable_wake - enable PCI device as wakeup event source
> + * __pci_enable_wake - enable PCI device as wakeup event source
>   * @dev: PCI device affected
>   * @state: PCI state from which device will issue wakeup events
>   * @enable: True to enable event generation; false to disable
> @@ -1911,7 +1911,7 @@ EXPORT_SYMBOL(pci_pme_active);
>   * Error code depending on the platform is returned if both the platform and
>   * the native mechanism fail to enable the generation of wake-up events
>   */
> -int pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
> +static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
>  {
>  	int ret = 0;
>  
> @@ -1952,6 +1952,23 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
>  
>  	return ret;
>  }
> +
> +/**
> + * pci_enable_wake - change wakeup settings for a PCI device
> + * @pci_dev: Target device
> + * @state: PCI state from which device will issue wakeup events
> + * @enable: Whether or not to enable event generation
> + *
> + * If @enable is set, check device_may_wakeup() for the device before calling
> + * __pci_enable_wake() for it.
> + */
> +int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable)
> +{
> +	if (enable && !device_may_wakeup(&pci_dev->dev))
> +		return -EINVAL;
> +
> +	return __pci_enable_wake(pci_dev, state, enable);
> +}
>  EXPORT_SYMBOL(pci_enable_wake);
>  
>  /**
> @@ -1964,9 +1981,9 @@ EXPORT_SYMBOL(pci_enable_wake);
>   * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI
>   * ordering constraints.
>   *
> - * This function only returns error code if the device is not capable of
> - * generating PME# from both D3_hot and D3_cold, and the platform is unable to
> - * enable wake-up power for it.
> + * This function only returns error code if the device is not allowed to wake
> + * up the system from sleep or it is not capable of generating PME# from both
> + * D3_hot and D3_cold and the platform is unable to enable wake-up power for it.
>   */
>  int pci_wake_from_d3(struct pci_dev *dev, bool enable)
>  {
> @@ -2097,7 +2114,7 @@ int pci_finish_runtime_suspend(struct pci_dev *dev)
>  
>  	dev->runtime_d3cold = target_state == PCI_D3cold;
>  
> -	pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
> +	__pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
>  
>  	error = pci_set_power_state(dev, target_state);
>  
>