PCI: Autosense device removal in pci_bridge_d3_update()

The algorithm to update the flag indicating whether a bridge may go to D3
makes a few optimizations based on whether the update was caused by the
removal of a device on the one hand, versus the addition of a device or the
change of its D3cold flags on the other hand.

The information whether the update pertains to a removal is currently
passed in by the caller, but the function may as well determine that itself
by examining the device in question, thereby allowing for a considerable
simplification and reduction of the code.

Out of several options to determine removal, I've chosen the function
device_is_registered() because it's cheap:  It merely returns the
dev->kobj.state_in_sysfs flag.  That flag is set through device_add() when
the root bus is scanned and cleared through device_remove().  The call to
pci_bridge_d3_update() happens after each of these calls, respectively, so
the ordering is correct.

No functional change intended.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index c288e5a525754dbebe3165f44e5cbe0569d7ec21..bc56cf19afd392c7b3feefa2cf5f070f059ed9e1 100644 (file)
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -320,7 +320,7 @@ void pci_bus_add_device(struct pci_dev *dev)
        pci_fixup_device(pci_fixup_final, dev);
        pci_create_sysfs_dev_files(dev);
        pci_proc_attach_device(dev);
-       pci_bridge_d3_device_changed(dev);
+       pci_bridge_d3_update(dev);
 
        dev->match_driver = true;
        retval = device_attach(&dev->dev);

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5d6f2970fd6f9d785852950a84046aec641f1f65..8200874ef5fc534c699c73a9b8afd300541da14c 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2281,14 +2281,14 @@ static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
 /*
  * pci_bridge_d3_update - Update bridge D3 capabilities
  * @dev: PCI device which is changed
- * @remove: Is the device being removed
  *
  * Update upstream bridge PM capabilities accordingly depending on if the
  * device PM configuration was changed or the device is being removed.  The
  * change is also propagated upstream.
  */
-static void pci_bridge_d3_update(struct pci_dev *dev, bool remove)
+void pci_bridge_d3_update(struct pci_dev *dev)
 {
+       bool remove = !device_is_registered(&dev->dev);
        struct pci_dev *bridge;
        bool d3cold_ok = true;
 
@@ -2315,35 +2315,10 @@ static void pci_bridge_d3_update(struct pci_dev *dev, bool remove)
        if (bridge->bridge_d3 != d3cold_ok) {
                bridge->bridge_d3 = d3cold_ok;
                /* Propagate change to upstream bridges */
-               pci_bridge_d3_update(bridge, false);
+               pci_bridge_d3_update(bridge);
        }
 }
 
-/**
- * pci_bridge_d3_device_changed - Update bridge D3 capabilities on change
- * @dev: PCI device that was changed
- *
- * If a device is added or its PM configuration, such as is it allowed to
- * enter D3cold, is changed this function updates upstream bridge PM
- * capabilities accordingly.
- */
-void pci_bridge_d3_device_changed(struct pci_dev *dev)
-{
-       pci_bridge_d3_update(dev, false);
-}
-
-/**
- * pci_bridge_d3_device_removed - Update bridge D3 capabilities on remove
- * @dev: PCI device being removed
- *
- * Function updates upstream bridge PM capabilities based on other devices
- * still left on the bus.
- */
-void pci_bridge_d3_device_removed(struct pci_dev *dev)
-{
-       pci_bridge_d3_update(dev, true);
-}
-
 /**
  * pci_d3cold_enable - Enable D3cold for device
  * @dev: PCI device to handle
@@ -2356,7 +2331,7 @@ void pci_d3cold_enable(struct pci_dev *dev)
 {
        if (dev->no_d3cold) {
                dev->no_d3cold = false;
-               pci_bridge_d3_device_changed(dev);
+               pci_bridge_d3_update(dev);
        }
 }
 EXPORT_SYMBOL_GPL(pci_d3cold_enable);
@@ -2373,7 +2348,7 @@ void pci_d3cold_disable(struct pci_dev *dev)
 {
        if (!dev->no_d3cold) {
                dev->no_d3cold = true;
-               pci_bridge_d3_device_changed(dev);
+               pci_bridge_d3_update(dev);
        }
 }
 EXPORT_SYMBOL_GPL(pci_d3cold_disable);

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 451856210e1816b4cf3932e5e32675199353b2cd..27048bb88783754d71fe10d606eed119d56d59ad 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -85,8 +85,7 @@ void pci_pm_init(struct pci_dev *dev);
 void pci_ea_init(struct pci_dev *dev);
 void pci_allocate_cap_save_buffers(struct pci_dev *dev);
 void pci_free_cap_save_buffers(struct pci_dev *dev);
-void pci_bridge_d3_device_changed(struct pci_dev *dev);
-void pci_bridge_d3_device_removed(struct pci_dev *dev);
+void pci_bridge_d3_update(struct pci_dev *dev);
 
 static inline void pci_wakeup_event(struct pci_dev *dev)
 {

diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index f9357e09e9b30131d631361a9d0092a1e19980bb..73a03d3825903b4cf8674c727d5eac8cf2cb082c 100644 (file)
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -40,7 +40,7 @@ static void pci_destroy_dev(struct pci_dev *dev)
        list_del(&dev->bus_list);
        up_write(&pci_bus_sem);
 
-       pci_bridge_d3_device_removed(dev);
+       pci_bridge_d3_update(dev);
        pci_free_resources(dev);
        put_device(&dev->dev);
 }