diff options
| author | Keith Busch <keith.busch@intel.com> | 2017-02-03 16:46:13 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-02-10 14:36:14 -0600 |
| commit | abdbf4d635a9a8c956bb9757a9d4f08c2abe1f97 (patch) | |
| tree | 505f28df23e7cf1413c3537f258f722f2627492d /drivers/pci/pcie | |
| parent | 87b336d003d47876e376d943be3c9d35152f3b86 (diff) | |
PCI/DPC: Wait for Root Port busy to clear
Per PCIe r3.1, sec 6.2.10 and sec 7.13.4, on Root Ports that support "RP
Extensions for DPC",
When the DPC Trigger Status bit is Set and the DPC RP Busy bit is Set,
software must leave the Root Port in DPC until the DPC RP Busy bit reads
0b.
Wait up to 1 second for the Root Port to become non-busy.
[bhelgaas: changelog, spec references]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pcie')
| -rw-r--r-- | drivers/pci/pcie/pcie-dpc.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c index 5a261fd4f03d..d4d70ef4a2d7 100644 --- a/drivers/pci/pcie/pcie-dpc.c +++ b/drivers/pci/pcie/pcie-dpc.c @@ -19,8 +19,28 @@ struct dpc_dev { struct pcie_device *dev; struct work_struct work; int cap_pos; + bool rp; }; +static int dpc_wait_rp_inactive(struct dpc_dev *dpc) +{ + unsigned long timeout = jiffies + HZ; + struct pci_dev *pdev = dpc->dev->port; + u16 status; + + pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status); + while (status & PCI_EXP_DPC_RP_BUSY && + !time_after(jiffies, timeout)) { + msleep(10); + pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status); + } + if (status & PCI_EXP_DPC_RP_BUSY) { + dev_warn(&pdev->dev, "DPC root port still busy\n"); + return -EBUSY; + } + return 0; +} + static void dpc_wait_link_inactive(struct pci_dev *pdev) { unsigned long timeout = jiffies + HZ; @@ -33,7 +53,7 @@ static void dpc_wait_link_inactive(struct pci_dev *pdev) pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); } if (lnk_status & PCI_EXP_LNKSTA_DLLLA) - dev_warn(&pdev->dev, "Link state not disabled for DPC event"); + dev_warn(&pdev->dev, "Link state not disabled for DPC event\n"); } static void interrupt_event_handler(struct work_struct *work) @@ -52,6 +72,8 @@ static void interrupt_event_handler(struct work_struct *work) pci_unlock_rescan_remove(); dpc_wait_link_inactive(pdev); + if (dpc->rp && dpc_wait_rp_inactive(dpc)) + return; pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT); } @@ -115,6 +137,8 @@ static int dpc_probe(struct pcie_device *dev) pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap); pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl); + dpc->rp = (cap & PCI_EXP_DPC_CAP_RP_EXT); + ctl |= PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN; pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl); |