diff options
| -rw-r--r-- | drivers/pci/pci.c | 41 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 5 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 9 | ||||
| -rw-r--r-- | include/linux/pci.h | 1 |
4 files changed, 37 insertions, 19 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e3a49f66982d..fc2ecb7fe081 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1283,7 +1283,9 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) { int delay = 1; bool retrain = false; - struct pci_dev *bridge; + struct pci_dev *root, *bridge; + + root = pcie_find_root_port(dev); if (pci_is_pcie(dev)) { bridge = pci_upstream_bridge(dev); @@ -1292,16 +1294,23 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) } /* - * After reset, the device should not silently discard config - * requests, but it may still indicate that it needs more time by - * responding to them with CRS completions. The Root Port will - * generally synthesize ~0 (PCI_ERROR_RESPONSE) data to complete - * the read (except when CRS SV is enabled and the read was for the - * Vendor ID; in that case it synthesizes 0x0001 data). + * The caller has already waited long enough after a reset that the + * device should respond to config requests, but it may respond + * with Request Retry Status (RRS) if it needs more time to + * initialize. + * + * If the device is below a Root Port with Configuration RRS + * Software Visibility enabled, reading the Vendor ID returns a + * special data value if the device responded with RRS. Read the + * Vendor ID until we get non-RRS status. * - * Wait for the device to return a non-CRS completion. Read the - * Command register instead of Vendor ID so we don't have to - * contend with the CRS SV value. + * If there's no Root Port or Configuration RRS Software Visibility + * is not enabled, the device may still respond with RRS, but + * hardware may retry the config request. If no retries receive + * Successful Completion, hardware generally synthesizes ~0 + * (PCI_ERROR_RESPONSE) data to complete the read. Reading Vendor + * ID for VFs and non-existent devices also returns ~0, so read the + * Command register until it returns something other than ~0. */ for (;;) { u32 id; @@ -1311,9 +1320,15 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) return -ENOTTY; } - pci_read_config_dword(dev, PCI_COMMAND, &id); - if (!PCI_POSSIBLE_ERROR(id)) - break; + if (root && root->config_crs_sv) { + pci_read_config_dword(dev, PCI_VENDOR_ID, &id); + if (!pci_bus_crs_vendor_id(id)) + break; + } else { + pci_read_config_dword(dev, PCI_COMMAND, &id); + if (!PCI_POSSIBLE_ERROR(id)) + break; + } if (delay > timeout) { pci_warn(dev, "not ready %dms after %s; giving up\n", diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 79c8398f3938..fa1997bc2667 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -139,6 +139,11 @@ bool pci_bridge_d3_possible(struct pci_dev *dev); void pci_bridge_d3_update(struct pci_dev *dev); int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type); +static inline bool pci_bus_crs_vendor_id(u32 l) +{ + return (l & 0xffff) == PCI_VENDOR_ID_PCI_SIG; +} + static inline void pci_wakeup_event(struct pci_dev *dev) { /* Wait 100 ms before the system can be put into a sleep state. */ diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b14b9876c030..b1615da9eb6b 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1209,9 +1209,11 @@ static void pci_enable_crs(struct pci_dev *pdev) /* Enable CRS Software Visibility if supported */ pcie_capability_read_word(pdev, PCI_EXP_RTCAP, &root_cap); - if (root_cap & PCI_EXP_RTCAP_CRSVIS) + if (root_cap & PCI_EXP_RTCAP_CRSVIS) { pcie_capability_set_word(pdev, PCI_EXP_RTCTL, PCI_EXP_RTCTL_CRSSVE); + pdev->config_crs_sv = 1; + } } static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, @@ -2343,11 +2345,6 @@ struct pci_dev *pci_alloc_dev(struct pci_bus *bus) } EXPORT_SYMBOL(pci_alloc_dev); -static bool pci_bus_crs_vendor_id(u32 l) -{ - return (l & 0xffff) == PCI_VENDOR_ID_PCI_SIG; -} - static bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, int timeout) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 4cf89a4b4cbc..121d8d94d6d0 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -371,6 +371,7 @@ struct pci_dev { can be generated */ unsigned int pme_poll:1; /* Poll device's PME status bit */ unsigned int pinned:1; /* Whether this dev is pinned */ + unsigned int config_crs_sv:1; /* Config CRS software visibility */ unsigned int imm_ready:1; /* Supports Immediate Readiness */ unsigned int d1_support:1; /* Low power state D1 is supported */ unsigned int d2_support:1; /* Low power state D2 is supported */ |