From 1ed276a7b9d84626e5243fc54863440c74a4100a Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Fri, 28 Oct 2016 10:52:06 +0200 Subject: [PATCH] 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 Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki --- drivers/pci/bus.c | 2 +- drivers/pci/pci.c | 35 +++++------------------------------ drivers/pci/pci.h | 3 +-- drivers/pci/remove.c | 2 +- 4 files changed, 8 insertions(+), 34 deletions(-) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index c288e5a52575..bc56cf19afd3 100644 --- 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 5d6f2970fd6f..8200874ef5fc 100644 --- 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 451856210e18..27048bb88783 100644 --- 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 f9357e09e9b3..73a03d382590 100644 --- 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); } -- GitLab