Rafael J. Wysocki 379021d5c0 PCI / PM: Extend PME polling to all PCI devices ... The land of PCI power management is a land of sorrow and ugliness, especially in the area of signaling events by devices. There are devices that set their PME Status bits, but don't really bother to send a PME message or assert PME#. There are hardware vendors who don't connect PME# lines to the system core logic (they know who they are). There are PCI Express Root Ports that don't bother to trigger interrupts when they receive PME messages from the devices below. There are ACPI BIOSes that forget to provide _PRW methods for devices capable of signaling wakeup. Finally, there are BIOSes that do provide _PRW methods for such devices, but then don't bother to call Notify() for those devices from the corresponding _Lxx/_Exx GPE-handling methods. In all of these cases the kernel doesn't have a chance to receive a proper notification that it should wake up a device, so devices stay in low-power states forever. Worse yet, in some cases they continuously send PME Messages that are silently ignored, because the kernel simply doesn't know that it should clear the device's PME Status bit. This problem was first observed for "parallel" (non-Express) PCI devices on add-on cards and Matthew Garrett addressed it by adding code that polls PME Status bits of such devices, if they are enabled to signal PME, to the kernel. Recently, however, it has turned out that PCI Express devices are also affected by this issue and that it is not limited to add-on devices, so it seems necessary to extend the PME polling to all PCI devices, including PCI Express and planar ones. Still, it would be wasteful to poll the PME Status bits of devices that are known to receive proper PME notifications, so make the kernel (1) poll the PME Status bits of all PCI and PCIe devices enabled to signal PME and (2) disable the PME Status polling for devices for which correct PME notifications are received. Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>		2011-10-14 09:05:31 -07:00
..
aer	PCI: PCIe AER: add aer_recover_queue	2011-07-22 08:25:37 -07:00
aspm.c	PCIe ASPM: forcedly -> forcibly	2011-06-29 14:24:14 +02:00
Kconfig	kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT	2011-01-20 17:02:05 -08:00
Makefile	PCI: PCIe: Move PCIe PME code to the pcie directory	2010-08-24 13:47:48 -07:00
pme.c	PCI / PM: Extend PME polling to all PCI devices	2011-10-14 09:05:31 -07:00
portdrv_acpi.c	PCI/ACPI: Request _OSC control once for each root bridge (v3)	2011-01-14 08:55:41 -08:00
portdrv_bus.c
portdrv_core.c	PCI: Disable ASPM when _OSC control is not granted for PCIe services	2011-03-21 09:41:08 -07:00
portdrv_pci.c	PCI/PCIe: Clear Root PME Status bits early during system resume	2010-12-23 12:54:03 -08:00
portdrv.h	PCI/ACPI: Request _OSC control once for each root bridge (v3)	2011-01-14 08:55:41 -08:00