From: Keith Busch Date: Wed, 5 Sep 2018 20:35:41 +0000 (-0600) Subject: PCI: pciehp: Fix hot-add vs powerfault detection order X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=34fb6bf9b13aef4ca14224f2175ecd189e98160b;p=openwrt%2Fstaging%2Fblogic.git PCI: pciehp: Fix hot-add vs powerfault detection order If both hot-add and power fault were observed in a single interrupt, we handled the hot-add first, then the power fault, in this path: pciehp_ist if (events & (PDC | DLLSC)) pciehp_handle_presence_or_link_change case OFF_STATE: pciehp_enable_slot __pciehp_enable_slot board_added pciehp_power_on_slot ctrl->power_fault_detected = 0 pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC) pciehp_green_led_on(p_slot) # power LED on pciehp_set_attention_status(p_slot, 0) # attention LED off if ((events & PFD) && !ctrl->power_fault_detected) ctrl->power_fault_detected = 1 pciehp_set_attention_status(1) # attention LED on pciehp_green_led_off(slot) # power LED off This left the attention indicator on (even though the hot-add succeeded) and the power indicator off (even though the slot power was on). Fix this by checking for power faults before checking for new devices. Prior to 0e94916e6091, this was successful because everything was chained through work queues and the order was: INT_PRESENCE_ON -> INT_POWER_FAULT -> ENABLE_REQ The ENABLE_REQ cleared the power fault at the end, but now everything is handled inline with the interrupt thread, such that the work ENABLE_REQ was doing happens before power fault handling now. Fixes: 0e94916e6091 ("PCI: pciehp: Handle events synchronously") Signed-off-by: Keith Busch [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner --- diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 7136e3430925..a938abdb41ce 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -496,7 +496,7 @@ int pciehp_power_on_slot(struct slot *slot) u16 slot_status; int retval; - /* Clear sticky power-fault bit from previous power failures */ + /* Clear power-fault bit from previous power failures */ pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); if (slot_status & PCI_EXP_SLTSTA_PFD) pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, @@ -646,6 +646,14 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) pciehp_handle_button_press(slot); } + /* Check Power Fault Detected */ + if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) { + ctrl->power_fault_detected = 1; + ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(slot)); + pciehp_set_attention_status(slot, 1); + pciehp_green_led_off(slot); + } + /* * Disable requests have higher priority than Presence Detect Changed * or Data Link Layer State Changed events. @@ -657,14 +665,6 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) pciehp_handle_presence_or_link_change(slot, events); up_read(&ctrl->reset_lock); - /* Check Power Fault Detected */ - if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) { - ctrl->power_fault_detected = 1; - ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(slot)); - pciehp_set_attention_status(slot, 1); - pciehp_green_led_off(slot); - } - pci_config_pm_runtime_put(pdev); wake_up(&ctrl->requester); return IRQ_HANDLED;