@@ -760,6 +760,7 @@ static inline void pcie_ecrc_get_policy(char *str) { }
void pcie_reset_lbms_count(struct pci_dev *port);
int pcie_lbms_count(struct pci_dev *port, unsigned long *val);
int pcie_poll_sltctl_cmd(struct pci_dev *dev, int timeout_ms);
+void pcie_disable_hp_interrupts_early(struct pci_dev *dev);
#else
static inline void pcie_reset_lbms_count(struct pci_dev *port) {}
static inline int pcie_lbms_count(struct pci_dev *port, unsigned long *val)
@@ -770,6 +771,7 @@ static inline int pcie_poll_sltctl_cmd(struct pci_dev *dev, int timeout_ms)
{
return 0;
}
+static inline void pcie_disable_hp_interrupts_early(struct pci_dev *dev) {}
#endif
struct pci_dev_reset_methods {
@@ -230,6 +230,22 @@ int pcie_poll_sltctl_cmd(struct pci_dev *dev, int timeout_ms)
return ret;
}
+void pcie_disable_hp_interrupts_early(struct pci_dev *dev)
+{
+ u16 slot_ctrl = 0;
+
+ pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &slot_ctrl);
+ /* Bail out early if it is already disabled */
+ if (!(slot_ctrl & (PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE)))
+ return;
+
+ pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
+ PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
+
+ if (pcie_poll_sltctl_cmd(dev, 1000))
+ pci_info(dev, "Timeout on disabling PCIe hot-plug interrupt\n");
+}
+
/**
* get_port_device_capability - discover capabilities of a PCI Express port
* @dev: PCI Express port to examine
@@ -255,8 +271,7 @@ static int get_port_device_capability(struct pci_dev *dev)
* Disable hot-plug interrupts in case they have been enabled
* by the BIOS and the hot-plug service driver is not loaded.
*/
- pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
- PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
+ pcie_disable_hp_interrupts_early(dev);
}
#ifdef CONFIG_PCIEAER
There was problem reported by firmware developers that they received two PCIe hotplug commands in very short intervals on an ARM server, which doesn't comply with PCIe spec, and broke their state machine and work flow. According to PCIe 6.1 spec, section 6.7.3.2, software needs to wait at least 1 second for the command-complete event, before resending the command or sending a new command. In the failure case, the first PCIe hotplug command firmware received is from get_port_device_capability(), which sends command to disable PCIe hotplug interrupts without waiting for its completion, and the second command comes from pcie_enable_notification() of pciehp driver, which enables hotplug interrupts again. Fix it by adding the necessary wait to comply with PCIe spec. Fixes: 2bd50dd800b5 ("PCI: PCIe: Disable PCIe port services during port initialization") Originally-by: Liguang Zhang <zhangliguang@linux.alibaba.com> Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> --- drivers/pci/pci.h | 2 ++ drivers/pci/pcie/portdrv.c | 19 +++++++++++++++++-- 2 files changed, 19 insertions(+), 2 deletions(-)