diff options
| -rw-r--r-- | src/southbridge/intel/bd82x6x/pch.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/src/southbridge/intel/bd82x6x/pch.c b/src/southbridge/intel/bd82x6x/pch.c index ae8ed9b15c..c668f9a6b9 100644 --- a/src/southbridge/intel/bd82x6x/pch.c +++ b/src/southbridge/intel/bd82x6x/pch.c @@ -6,6 +6,7 @@ #include <device/pci.h> #include <device/pci_ops.h> #include <string.h> +#include <timer.h> #include "chip.h" #include "pch.h" @@ -296,6 +297,52 @@ static void pch_pcie_devicetree_update( sizeof(new_hotplug_map)); } +static void check_device_present(struct device *dev) +{ + struct southbridge_intel_bd82x6x_config *config = dev->chip_info; + struct stopwatch timeout; + bool present, hot_plugable; + uint32_t cap; + + /* Set slot implemented. */ + cap = pci_find_capability(dev, PCI_CAP_ID_PCIE); + pci_or_config16(dev, cap + PCI_EXP_FLAGS, PCI_EXP_FLAGS_SLOT); + + /* + * By setting the PCI_EXP_FLAGS_SLOT bit in register PCI_EXP_FLAGS the + * PCI_EXP_SLTSTA_PDS bit will be updated with in band device + * detection from the PCIe PHY. While this is primarly used for PCIe + * hot-plug detection, it is more reliable than probing for downstream + * devices by reading DID/VID PCI registers of such. + * + * Usually the PCI_EXP_FLAGS_SLOT isn't set for integrated devices, + * but to simplify device detection it's set for all ports. + * + * It also allows to detect device before PCI enumeration has run. + */ + hot_plugable = config && config->pcie_hotplug_map[PCI_FUNC(dev->path.pci.devfn)]; + present = !!(pci_read_config16(dev, cap + PCI_EXP_SLTSTA) & PCI_EXP_SLTSTA_PDS); + + printk(BIOS_DEBUG, "%s: %s downstream device\n", + dev_path(dev), present ? "Found a" : "No"); + + if (!present && !hot_plugable) { + /* No device present. */ + stopwatch_init_usecs_expire(&timeout, 50 * 1000); + pci_or_config32(dev, 0x338, 1 << 26); + + while (!stopwatch_expired(&timeout)) { + if ((pci_read_config32(dev, 0x328) & (0x1f << 23)) == 0) + break; + udelay(100); + } + dev->enabled = 0; + } else if (present && !hot_plugable && !dev->enabled) { + /* Port will be disabled, but device present. Disable link. */ + pci_or_config32(dev, cap + PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_LD); + } +} + /* Special handling for PCIe Root Port devices */ static void pch_pcie_enable(struct device *dev) { @@ -304,6 +351,8 @@ static void pch_pcie_enable(struct device *dev) if (!config) return; + check_device_present(dev); + /* * Save a copy of the Root Port Function Number map when * starting to walk the list of PCIe Root Ports so it can |