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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-11-24 22:44:00 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-12-07 15:45:11 +0300
commit7482c5cb90e5a7f9e9e12dd154d405e0219656e3 (patch)
treeedd2afe6ddaed2fa6ec3a395492e48989c5c7202 /drivers/pci/pci-acpi.c
parentd60cd06331a3566d3305b3c7b566e79edf4e2095 (diff)
downloadlinux-7482c5cb90e5a7f9e9e12dd154d405e0219656e3.tar.xz
PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup()
The idea behind acpi_pm_set_bridge_wakeup() was to allow bridges to be reference counted for wakeup enabling, because they may be enabled to signal wakeup on behalf of their subordinate devices and that may happen for multiple times in a row, whereas for the other devices it only makes sense to enable wakeup signaling once. However, this becomes problematic if the bridge itself is suspended, because it is treated as a "regular" device in that case and the reference counting doesn't work. For instance, suppose that there are two devices below a bridge and they both can signal wakeup. Every time one of them is suspended, wakeup signaling is enabled for the bridge, so when they both have been suspended, the bridge's wakeup reference counter value is 2. Say that the bridge is suspended subsequently and acpi_pci_wakeup() is called for it. Because the bridge can signal wakeup, that function will invoke acpi_pm_set_device_wakeup() to configure it and __acpi_pm_set_device_wakeup() will be called with the last argument equal to 1. This causes __acpi_device_wakeup_enable() invoked by it to omit the reference counting, because the reference counter of the target device (the bridge) is 2 at that time. Now say that the bridge resumes and one of the device below it resumes too, so the bridge's reference counter becomes 0 and wakeup signaling is disabled for it, but there is still the other suspended device which may need the bridge to signal wakeup on its behalf and that is not going to work. To address this scenario, use wakeup enable reference counting for all devices, not just for bridges, so drop the last argument from __acpi_device_wakeup_enable() and __acpi_pm_set_device_wakeup(), which causes acpi_pm_set_device_wakeup() and acpi_pm_set_bridge_wakeup() to become identical, so drop the latter and use the former instead of it everywhere. Fixes: 1ba51a7c1496 ("ACPI / PCI / PM: Rework acpi_pci_propagate_wakeup()") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Cc: 4.14+ <stable@vger.kernel.org> # 4.14+
Diffstat (limited to 'drivers/pci/pci-acpi.c')
-rw-r--r--drivers/pci/pci-acpi.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index bf03648c2072..745a4e0c4994 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1060,7 +1060,7 @@ static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
{
while (bus->parent) {
if (acpi_pm_device_can_wakeup(&bus->self->dev))
- return acpi_pm_set_bridge_wakeup(&bus->self->dev, enable);
+ return acpi_pm_set_device_wakeup(&bus->self->dev, enable);
bus = bus->parent;
}
@@ -1068,7 +1068,7 @@ static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
/* We have reached the root bus. */
if (bus->bridge) {
if (acpi_pm_device_can_wakeup(bus->bridge))
- return acpi_pm_set_bridge_wakeup(bus->bridge, enable);
+ return acpi_pm_set_device_wakeup(bus->bridge, enable);
}
return 0;
}