From: Bjorn Helgaas Date: Tue, 6 Sep 2016 21:24:37 +0000 (-0500) Subject: PCI/AER: Remove aerdriver.forceload kernel parameter X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7ece14175376051b18a9b97f0e6125cb8b864155;p=linux-beck.git PCI/AER: Remove aerdriver.forceload kernel parameter Per the PCI Firmware spec, r3.0, sec 4.5.1, on ACPI systems, the OS must not use AER unless _OSC is present and _OSC grants AER control to the OS. The aerdriver.forceload kernel parameter was a way to enable Linux AER support on ACPI systems that lack _OSC or fail to grant control the the OS. Enabling Linux AER support when the firmware doesn't want us to is a recipe for problems, e.g., the firmware might be handling AER itself. Remove the aerdriver.forceload kernel parameter and related supporting code. Signed-off-by: Bjorn Helgaas --- diff --git a/Documentation/PCI/pcieaer-howto.txt b/Documentation/PCI/pcieaer-howto.txt index 4956df36c59d..ea8cafba255c 100644 --- a/Documentation/PCI/pcieaer-howto.txt +++ b/Documentation/PCI/pcieaer-howto.txt @@ -49,21 +49,17 @@ depends on CONFIG_PCIEPORTBUS, so pls. set CONFIG_PCIEPORTBUS=y and CONFIG_PCIEAER = y. 2.2 Load PCI Express AER Root Driver -There is a case where a system has AER support in BIOS. Enabling the AER -Root driver and having AER support in BIOS may result unpredictable -behavior. To avoid this conflict, a successful load of the AER Root driver -requires ACPI _OSC support in the BIOS to allow the AER Root driver to -request for native control of AER. See the PCI FW 3.0 Specification for -details regarding OSC usage. Currently, lots of firmwares don't provide -_OSC support while they use PCI Express. To support such firmwares, -forceload, a parameter of type bool, could enable AER to continue to -be initiated although firmwares have no _OSC support. To enable the -walkaround, pls. add aerdriver.forceload=y to kernel boot parameter line -when booting kernel. Note that forceload=n by default. + +Some systems have AER support in firmware. Enabling Linux AER support at +the same time the firmware handles AER may result in unpredictable +behavior. Therefore, Linux does not handle AER events unless the firmware +grants AER control to the OS via the ACPI _OSC method. See the PCI FW 3.0 +Specification for details regarding _OSC usage. 2.3 AER error output -When a PCI-E AER error is captured, an error message will be outputted to -console. If it's a correctable error, it is outputted as a warning. + +When a PCIe AER error is captured, an error message will be output to +console. If it's a correctable error, it is output as a warning. Otherwise, it is printed as an error. So users could choose different log level to filter out correctable error messages. diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c index 48d21e0edd56..08ce257077db 100644 --- a/drivers/pci/pcie/aer/aerdrv.c +++ b/drivers/pci/pcie/aer/aerdrv.c @@ -70,7 +70,7 @@ static int pcie_aer_disable; void pci_no_aer(void) { - pcie_aer_disable = 1; /* has priority over 'forceload' */ + pcie_aer_disable = 1; } bool pci_aer_available(void) @@ -304,11 +304,6 @@ static int aer_probe(struct pcie_device *dev) struct aer_rpc *rpc; struct device *device = &dev->device; - /* Init */ - status = aer_init(dev); - if (status) - return status; - /* Alloc rpc data structure */ rpc = aer_alloc_rpc(dev); if (!rpc) { diff --git a/drivers/pci/pcie/aer/aerdrv.h b/drivers/pci/pcie/aer/aerdrv.h index 945c939a86c5..f15ca8dc3882 100644 --- a/drivers/pci/pcie/aer/aerdrv.h +++ b/drivers/pci/pcie/aer/aerdrv.h @@ -105,7 +105,6 @@ static inline pci_ers_result_t merge_result(enum pci_ers_result orig, } extern struct bus_type pcie_port_bus_type; -int aer_init(struct pcie_device *dev); void aer_isr(struct work_struct *work); void aer_print_error(struct pci_dev *dev, struct aer_err_info *info); void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info); @@ -121,11 +120,4 @@ static inline int pcie_aer_get_firmware_first(struct pci_dev *pci_dev) return 0; } #endif - -static inline void pcie_aer_force_firmware_first(struct pci_dev *pci_dev, - int enable) -{ - pci_dev->__aer_firmware_first = !!enable; - pci_dev->__aer_firmware_first_valid = 1; -} #endif /* _AERDRV_H_ */ diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c index f8a9b17da949..8262527e7fed 100644 --- a/drivers/pci/pcie/aer/aerdrv_core.c +++ b/drivers/pci/pcie/aer/aerdrv_core.c @@ -27,9 +27,6 @@ #include #include "aerdrv.h" -static bool forceload; -module_param(forceload, bool, 0); - #define PCI_EXP_AER_FLAGS (PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \ PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE) @@ -811,19 +808,3 @@ void aer_isr(struct work_struct *work) aer_isr_one_error(p_device, &e_src); mutex_unlock(&rpc->rpc_mutex); } - -/** - * aer_init - provide AER initialization - * @dev: pointer to AER pcie device - * - * Invoked when AER service driver is loaded. - */ -int aer_init(struct pcie_device *dev) -{ - if (forceload) { - dev_printk(KERN_DEBUG, &dev->device, - "aerdrv forceload requested.\n"); - pcie_aer_force_firmware_first(dev->port, 0); - } - return 0; -}