diff mbox

[v2] PCI / PM: Avoid using device_may_wakeup() for runtime PM

Message ID 2677722.OnHOCzR3UZ@aspire.rjw.lan (mailing list archive)
State Mainlined
Headers show

Commit Message

Rafael J. Wysocki June 23, 2017, 12:58 p.m. UTC
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

pci_target_state() calls device_may_wakeup() which checks whether
or not the device may wake up the system from sleep states, but
pci_target_state() is used for runtime PM too.

Since runtime PM is expected to always enable remote wakeup if
possible, modify pci_target_state() to take additional argument
indicating whether or not it should look for a state from which
the device can signal wakeup and pass either the return value
of device_can_wakeup(), or "false" (if the device itself is not
wakeup-capable) to it from the code related to runtime PM.

While at it, fix the comment in pci_dev_run_wake() which is not
about sleep states.

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

-> v2:

Passing "true" as the second argument to pci_target_state() for runtime PM
might trigger suboptimal state choices to be made, so pass the return value
of device_can_wakeup() to it instead and pass "false" to it in pci_dev_run_wake(),
because that assumes device_can_wakeup() to return "false" already.

---
 drivers/pci/pci.c |   22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

Comments

Rafael J. Wysocki June 29, 2017, 10:37 p.m. UTC | #1
On Friday, June 23, 2017 02:58:11 PM Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> pci_target_state() calls device_may_wakeup() which checks whether
> or not the device may wake up the system from sleep states, but
> pci_target_state() is used for runtime PM too.
> 
> Since runtime PM is expected to always enable remote wakeup if
> possible, modify pci_target_state() to take additional argument
> indicating whether or not it should look for a state from which
> the device can signal wakeup and pass either the return value
> of device_can_wakeup(), or "false" (if the device itself is not
> wakeup-capable) to it from the code related to runtime PM.
> 
> While at it, fix the comment in pci_dev_run_wake() which is not
> about sleep states.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> 
> -> v2:
> 
> Passing "true" as the second argument to pci_target_state() for runtime PM
> might trigger suboptimal state choices to be made, so pass the return value
> of device_can_wakeup() to it instead and pass "false" to it in pci_dev_run_wake(),
> because that assumes device_can_wakeup() to return "false" already.

This was sent a week ago without any response so far.

Any concerns?

> ---
>  drivers/pci/pci.c |   22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> Index: linux-pm/drivers/pci/pci.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci.c
> +++ linux-pm/drivers/pci/pci.c
> @@ -1982,12 +1982,13 @@ EXPORT_SYMBOL(pci_wake_from_d3);
>  /**
>   * pci_target_state - find an appropriate low power state for a given PCI dev
>   * @dev: PCI device
> + * @wakeup: Whether or not wakeup functionality will be enabled for the device.
>   *
>   * Use underlying platform code to find a supported low power state for @dev.
>   * If the platform can't manage @dev, return the deepest state from which it
>   * can generate wake events, based on any available PME info.
>   */
> -static pci_power_t pci_target_state(struct pci_dev *dev)
> +static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
>  {
>  	pci_power_t target_state = PCI_D3hot;
>  
> @@ -2024,7 +2025,7 @@ static pci_power_t pci_target_state(stru
>  	if (dev->current_state == PCI_D3cold)
>  		target_state = PCI_D3cold;
>  
> -	if (device_may_wakeup(&dev->dev)) {
> +	if (wakeup) {
>  		/*
>  		 * Find the deepest state from which the device can generate
>  		 * wake-up events, make it the target state and enable device
> @@ -2050,13 +2051,14 @@ static pci_power_t pci_target_state(stru
>   */
>  int pci_prepare_to_sleep(struct pci_dev *dev)
>  {
> -	pci_power_t target_state = pci_target_state(dev);
> +	bool wakeup = device_may_wakeup(&dev->dev);
> +	pci_power_t target_state = pci_target_state(dev, wakeup);
>  	int error;
>  
>  	if (target_state == PCI_POWER_ERROR)
>  		return -EIO;
>  
> -	pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
> +	pci_enable_wake(dev, target_state, wakeup);
>  
>  	error = pci_set_power_state(dev, target_state);
>  
> @@ -2089,9 +2091,10 @@ EXPORT_SYMBOL(pci_back_from_sleep);
>   */
>  int pci_finish_runtime_suspend(struct pci_dev *dev)
>  {
> -	pci_power_t target_state = pci_target_state(dev);
> +	pci_power_t target_state;
>  	int error;
>  
> +	target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
>  	if (target_state == PCI_POWER_ERROR)
>  		return -EIO;
>  
> @@ -2127,8 +2130,8 @@ bool pci_dev_run_wake(struct pci_dev *de
>  	if (!dev->pme_support)
>  		return false;
>  
> -	/* PME-capable in principle, but not from the intended sleep state */
> -	if (!pci_pme_capable(dev, pci_target_state(dev)))
> +	/* PME-capable in principle, but not from the target power state */
> +	if (!pci_pme_capable(dev, pci_target_state(dev, false)))
>  		return false;
>  
>  	while (bus->parent) {
> @@ -2163,9 +2166,10 @@ EXPORT_SYMBOL_GPL(pci_dev_run_wake);
>  bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
>  {
>  	struct device *dev = &pci_dev->dev;
> +	bool wakeup = device_may_wakeup(dev);
>  
>  	if (!pm_runtime_suspended(dev)
> -	    || pci_target_state(pci_dev) != pci_dev->current_state
> +	    || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
>  	    || platform_pci_need_resume(pci_dev)
>  	    || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME))
>  		return false;
> @@ -2183,7 +2187,7 @@ bool pci_dev_keep_suspended(struct pci_d
>  	spin_lock_irq(&dev->power.lock);
>  
>  	if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold &&
> -	    !device_may_wakeup(dev))
> +	    !wakeup)
>  		__pci_pme_active(pci_dev, false);
>  
>  	spin_unlock_irq(&dev->power.lock);
>
Mika Westerberg June 30, 2017, 8:44 a.m. UTC | #2
On Fri, Jun 30, 2017 at 12:37:00AM +0200, Rafael J. Wysocki wrote:
> On Friday, June 23, 2017 02:58:11 PM Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > 
> > pci_target_state() calls device_may_wakeup() which checks whether
> > or not the device may wake up the system from sleep states, but
> > pci_target_state() is used for runtime PM too.
> > 
> > Since runtime PM is expected to always enable remote wakeup if
> > possible, modify pci_target_state() to take additional argument
> > indicating whether or not it should look for a state from which
> > the device can signal wakeup and pass either the return value
> > of device_can_wakeup(), or "false" (if the device itself is not
> > wakeup-capable) to it from the code related to runtime PM.
> > 
> > While at it, fix the comment in pci_dev_run_wake() which is not
> > about sleep states.
> > 
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> > 
> > -> v2:
> > 
> > Passing "true" as the second argument to pci_target_state() for runtime PM
> > might trigger suboptimal state choices to be made, so pass the return value
> > of device_can_wakeup() to it instead and pass "false" to it in pci_dev_run_wake(),
> > because that assumes device_can_wakeup() to return "false" already.
> 
> This was sent a week ago without any response so far.
> 
> Any concerns?

No concerns from me.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Bjorn Helgaas June 30, 2017, 4:16 p.m. UTC | #3
On Fri, Jun 23, 2017 at 02:58:11PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> pci_target_state() calls device_may_wakeup() which checks whether
> or not the device may wake up the system from sleep states, but
> pci_target_state() is used for runtime PM too.
> 
> Since runtime PM is expected to always enable remote wakeup if
> possible, modify pci_target_state() to take additional argument
> indicating whether or not it should look for a state from which
> the device can signal wakeup and pass either the return value
> of device_can_wakeup(), or "false" (if the device itself is not
> wakeup-capable) to it from the code related to runtime PM.
> 
> While at it, fix the comment in pci_dev_run_wake() which is not
> about sleep states.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Applied with Mika's reviewed-by to pci/pm for v4.13, thanks!

> ---
> 
> -> v2:
> 
> Passing "true" as the second argument to pci_target_state() for runtime PM
> might trigger suboptimal state choices to be made, so pass the return value
> of device_can_wakeup() to it instead and pass "false" to it in pci_dev_run_wake(),
> because that assumes device_can_wakeup() to return "false" already.
> 
> ---
>  drivers/pci/pci.c |   22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> Index: linux-pm/drivers/pci/pci.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci.c
> +++ linux-pm/drivers/pci/pci.c
> @@ -1982,12 +1982,13 @@ EXPORT_SYMBOL(pci_wake_from_d3);
>  /**
>   * pci_target_state - find an appropriate low power state for a given PCI dev
>   * @dev: PCI device
> + * @wakeup: Whether or not wakeup functionality will be enabled for the device.
>   *
>   * Use underlying platform code to find a supported low power state for @dev.
>   * If the platform can't manage @dev, return the deepest state from which it
>   * can generate wake events, based on any available PME info.
>   */
> -static pci_power_t pci_target_state(struct pci_dev *dev)
> +static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
>  {
>  	pci_power_t target_state = PCI_D3hot;
>  
> @@ -2024,7 +2025,7 @@ static pci_power_t pci_target_state(stru
>  	if (dev->current_state == PCI_D3cold)
>  		target_state = PCI_D3cold;
>  
> -	if (device_may_wakeup(&dev->dev)) {
> +	if (wakeup) {
>  		/*
>  		 * Find the deepest state from which the device can generate
>  		 * wake-up events, make it the target state and enable device
> @@ -2050,13 +2051,14 @@ static pci_power_t pci_target_state(stru
>   */
>  int pci_prepare_to_sleep(struct pci_dev *dev)
>  {
> -	pci_power_t target_state = pci_target_state(dev);
> +	bool wakeup = device_may_wakeup(&dev->dev);
> +	pci_power_t target_state = pci_target_state(dev, wakeup);
>  	int error;
>  
>  	if (target_state == PCI_POWER_ERROR)
>  		return -EIO;
>  
> -	pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
> +	pci_enable_wake(dev, target_state, wakeup);
>  
>  	error = pci_set_power_state(dev, target_state);
>  
> @@ -2089,9 +2091,10 @@ EXPORT_SYMBOL(pci_back_from_sleep);
>   */
>  int pci_finish_runtime_suspend(struct pci_dev *dev)
>  {
> -	pci_power_t target_state = pci_target_state(dev);
> +	pci_power_t target_state;
>  	int error;
>  
> +	target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
>  	if (target_state == PCI_POWER_ERROR)
>  		return -EIO;
>  
> @@ -2127,8 +2130,8 @@ bool pci_dev_run_wake(struct pci_dev *de
>  	if (!dev->pme_support)
>  		return false;
>  
> -	/* PME-capable in principle, but not from the intended sleep state */
> -	if (!pci_pme_capable(dev, pci_target_state(dev)))
> +	/* PME-capable in principle, but not from the target power state */
> +	if (!pci_pme_capable(dev, pci_target_state(dev, false)))
>  		return false;
>  
>  	while (bus->parent) {
> @@ -2163,9 +2166,10 @@ EXPORT_SYMBOL_GPL(pci_dev_run_wake);
>  bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
>  {
>  	struct device *dev = &pci_dev->dev;
> +	bool wakeup = device_may_wakeup(dev);
>  
>  	if (!pm_runtime_suspended(dev)
> -	    || pci_target_state(pci_dev) != pci_dev->current_state
> +	    || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
>  	    || platform_pci_need_resume(pci_dev)
>  	    || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME))
>  		return false;
> @@ -2183,7 +2187,7 @@ bool pci_dev_keep_suspended(struct pci_d
>  	spin_lock_irq(&dev->power.lock);
>  
>  	if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold &&
> -	    !device_may_wakeup(dev))
> +	    !wakeup)
>  		__pci_pme_active(pci_dev, false);
>  
>  	spin_unlock_irq(&dev->power.lock);
>
diff mbox

Patch

Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -1982,12 +1982,13 @@  EXPORT_SYMBOL(pci_wake_from_d3);
 /**
  * pci_target_state - find an appropriate low power state for a given PCI dev
  * @dev: PCI device
+ * @wakeup: Whether or not wakeup functionality will be enabled for the device.
  *
  * Use underlying platform code to find a supported low power state for @dev.
  * If the platform can't manage @dev, return the deepest state from which it
  * can generate wake events, based on any available PME info.
  */
-static pci_power_t pci_target_state(struct pci_dev *dev)
+static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup)
 {
 	pci_power_t target_state = PCI_D3hot;
 
@@ -2024,7 +2025,7 @@  static pci_power_t pci_target_state(stru
 	if (dev->current_state == PCI_D3cold)
 		target_state = PCI_D3cold;
 
-	if (device_may_wakeup(&dev->dev)) {
+	if (wakeup) {
 		/*
 		 * Find the deepest state from which the device can generate
 		 * wake-up events, make it the target state and enable device
@@ -2050,13 +2051,14 @@  static pci_power_t pci_target_state(stru
  */
 int pci_prepare_to_sleep(struct pci_dev *dev)
 {
-	pci_power_t target_state = pci_target_state(dev);
+	bool wakeup = device_may_wakeup(&dev->dev);
+	pci_power_t target_state = pci_target_state(dev, wakeup);
 	int error;
 
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
-	pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
+	pci_enable_wake(dev, target_state, wakeup);
 
 	error = pci_set_power_state(dev, target_state);
 
@@ -2089,9 +2091,10 @@  EXPORT_SYMBOL(pci_back_from_sleep);
  */
 int pci_finish_runtime_suspend(struct pci_dev *dev)
 {
-	pci_power_t target_state = pci_target_state(dev);
+	pci_power_t target_state;
 	int error;
 
+	target_state = pci_target_state(dev, device_can_wakeup(&dev->dev));
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
@@ -2127,8 +2130,8 @@  bool pci_dev_run_wake(struct pci_dev *de
 	if (!dev->pme_support)
 		return false;
 
-	/* PME-capable in principle, but not from the intended sleep state */
-	if (!pci_pme_capable(dev, pci_target_state(dev)))
+	/* PME-capable in principle, but not from the target power state */
+	if (!pci_pme_capable(dev, pci_target_state(dev, false)))
 		return false;
 
 	while (bus->parent) {
@@ -2163,9 +2166,10 @@  EXPORT_SYMBOL_GPL(pci_dev_run_wake);
 bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
 {
 	struct device *dev = &pci_dev->dev;
+	bool wakeup = device_may_wakeup(dev);
 
 	if (!pm_runtime_suspended(dev)
-	    || pci_target_state(pci_dev) != pci_dev->current_state
+	    || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
 	    || platform_pci_need_resume(pci_dev)
 	    || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME))
 		return false;
@@ -2183,7 +2187,7 @@  bool pci_dev_keep_suspended(struct pci_d
 	spin_lock_irq(&dev->power.lock);
 
 	if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold &&
-	    !device_may_wakeup(dev))
+	    !wakeup)
 		__pci_pme_active(pci_dev, false);
 
 	spin_unlock_irq(&dev->power.lock);