From c39fae1416d59fd565606793f090cebe3720d50d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 17 Feb 2010 23:40:07 +0100 Subject: PCI PM: Make it possible to force using INTx for PCIe PME signaling Apparently, some machines may have problems with PCI run-time power management if MSIs are used for the native PCIe PME signaling. In particular, on the MSI Wind U-100 PCIe PME interrupts are not generated by a PCIe root port after a resume from suspend to RAM, if the system wake-up was triggered by a PME from the device attached to this port. [It doesn't help to free the interrupt on suspend and request it back on resume, even if that is done along with disabling the MSI and re-enabling it, respectively.] However, if INTx interrupts are used for this purpose on the same machine, everything works just fine. For this reason, add a kernel command line switch allowing one to request that MSIs be not used for the native PCIe PME signaling, introduce a DMI table allowing us to blacklist machines that need this switch to be set by default and put the MSI Wind U-100 into this table. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/pci/pcie/pme/pcie_pme.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers/pci/pcie/pme') diff --git a/drivers/pci/pcie/pme/pcie_pme.c b/drivers/pci/pcie/pme/pcie_pme.c index b5f96fb3cd83..51a69061b120 100644 --- a/drivers/pci/pcie/pme/pcie_pme.c +++ b/drivers/pci/pcie/pme/pcie_pme.c @@ -53,12 +53,22 @@ static bool pcie_pme_disabled; */ static bool pcie_pme_force_enable; +/* + * If this switch is set, MSI will not be used for PCIe PME signaling. This + * causes the PCIe port driver to use INTx interrupts only, but it turns out + * that using MSI for PCIe PME signaling doesn't play well with PCIe PME-based + * wake-up from system sleep states. + */ +bool pcie_pme_msi_disabled; + static int __init pcie_pme_setup(char *str) { if (!strcmp(str, "off")) pcie_pme_disabled = true; else if (!strcmp(str, "force")) pcie_pme_force_enable = true; + else if (!strcmp(str, "nomsi")) + pcie_pme_msi_disabled = true; return 1; } __setup("pcie_pme=", pcie_pme_setup); @@ -73,7 +83,9 @@ __setup("pcie_pme=", pcie_pme_setup); */ static bool pcie_pme_platform_setup(struct pcie_device *srv) { - return !pcie_pme_platform_notify(srv) || pcie_pme_force_enable; + if (!pcie_pme_platform_notify(srv)) + return true; + return pcie_pme_force_enable; } struct pcie_pme_service_data { -- cgit v1.2.2