From f3dbd802b3caf8da92173870bc270dda6b3f84ba Mon Sep 17 00:00:00 2001 From: Rajat Jain Date: Tue, 2 Sep 2014 16:26:00 -0700 Subject: PCI: Enable CRS Software Visibility for root port if it is supported Per PCIe r3.0, sec 2.3.2, an endpoint may respond to a Configuration Request with a Completion with Configuration Request Retry Status (CRS). This terminates the Configuration Request. When the CRS Software Visibility feature is disabled (as it is by default), a Root Complex must handle a CRS Completion by re-issuing the Configuration Request. This is invisible to software. From the CPU's point of view, an endpoint that always responds with CRS causes a hang because the Root Complex never supplies data to complete the CPU read. When CRS Software Visibility is enabled, a Root Complex that receives a CRS Completion for a read of the Vendor ID must return data of 0x0001. The Vendor ID of 0x0001 indicates to software that the endpoint is not ready. We now have more devices that require CRS Software Visibility. For example, a PLX 8713 NT bridge may respond with CRS until it has been configured via I2C, and the I2C configuration is completely independent of PCI enumeration. Enable CRS Software Visibility if it is supported. This allows a system with such a device to work (though the PCI core times out waiting for it to become ready, and we have to rescan the bus after it is ready). This essentially reverts ad7edfe04908 ("[PCI] Do not enable CRS Software Visibility by default"). The failures that led to ad7edfe04908 should be addressed by 89665a6a7140 ("PCI: Check only the Vendor ID to identify Configuration Request Retry"). [bhelgaas: changelog] Link: http://lkml.kernel.org/r/20071029061532.5d10dfc6@snowcone Link: http://lkml.kernel.org/r/alpine.LFD.0.9999.0712271023090.21557@woody.linux-foundation.org Signed-off-by: Rajat Jain Signed-off-by: Rajat Jain Signed-off-by: Guenter Roeck Signed-off-by: Bjorn Helgaas --- include/uapi/linux/pci_regs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 30db069..57d6e56 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -552,6 +552,7 @@ #define PCI_EXP_RTCTL_PMEIE 0x0008 /* PME Interrupt Enable */ #define PCI_EXP_RTCTL_CRSSVE 0x0010 /* CRS Software Visibility Enable */ #define PCI_EXP_RTCAP 30 /* Root Capabilities */ +#define PCI_EXP_RTCAP_CRSVIS 0x0001 /* CRS Software Visibility capability */ #define PCI_EXP_RTSTA 32 /* Root Status */ #define PCI_EXP_RTSTA_PME 0x00010000 /* PME status */ #define PCI_EXP_RTSTA_PENDING 0x00020000 /* PME pending */ -- cgit v1.1 From 846fc70986a65563a19ae86928c3acf34f12296d Mon Sep 17 00:00:00 2001 From: "Chen, Gong" Date: Wed, 13 Aug 2014 02:22:40 -0400 Subject: PCI/AER: Rename PCI_ERR_UNC_TRAIN to PCI_ERR_UNC_UND In PCIe r1.0, sec 5.10.2, bit 0 of the Uncorrectable Error Status, Mask, and Severity Registers was for "Training Error." In PCIe r1.1, sec 7.10.2, bit 0 was redefined to be "Undefined." Rename PCI_ERR_UNC_TRAIN to PCI_ERR_UNC_UND to reflect this change. No functional change. [bhelgaas: changelog] Signed-off-by: Chen, Gong Signed-off-by: Bjorn Helgaas --- include/uapi/linux/pci_regs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 30db069..99e3182 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -630,7 +630,7 @@ /* Advanced Error Reporting */ #define PCI_ERR_UNCOR_STATUS 4 /* Uncorrectable Error Status */ -#define PCI_ERR_UNC_TRAIN 0x00000001 /* Training */ +#define PCI_ERR_UNC_UND 0x00000001 /* Undefined */ #define PCI_ERR_UNC_DLP 0x00000010 /* Data Link Protocol */ #define PCI_ERR_UNC_SURPDN 0x00000020 /* Surprise Down */ #define PCI_ERR_UNC_POISON_TLP 0x00001000 /* Poisoned TLP */ -- cgit v1.1