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-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c26
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 5f1a27bfcb19..53433b37e181 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -565,7 +565,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
struct controller *ctrl = (struct controller *)dev_id;
struct pci_dev *pdev = ctrl_dev(ctrl);
struct device *parent = pdev->dev.parent;
- u16 status, events;
+ u16 status, events = 0;
/*
* Interrupts only occur in D3hot or shallower and only if enabled
@@ -590,6 +590,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
}
}
+read_status:
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
if (status == (u16) ~0) {
ctrl_info(ctrl, "%s: no response from device\n", __func__);
@@ -602,24 +603,37 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
* Slot Status contains plain status bits as well as event
* notification bits; right now we only want the event bits.
*/
- events = status & (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
- PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC |
- PCI_EXP_SLTSTA_DLLSC);
+ status &= PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
+ PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC |
+ PCI_EXP_SLTSTA_DLLSC;
/*
* If we've already reported a power fault, don't report it again
* until we've done something to handle it.
*/
if (ctrl->power_fault_detected)
- events &= ~PCI_EXP_SLTSTA_PFD;
+ status &= ~PCI_EXP_SLTSTA_PFD;
+ events |= status;
if (!events) {
if (parent)
pm_runtime_put(parent);
return IRQ_NONE;
}
- pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events);
+ if (status) {
+ pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events);
+
+ /*
+ * In MSI mode, all event bits must be zero before the port
+ * will send a new interrupt (PCIe Base Spec r5.0 sec 6.7.3.4).
+ * So re-read the Slot Status register in case a bit was set
+ * between read and write.
+ */
+ if (pci_dev_msi_enabled(pdev) && !pciehp_poll_mode)
+ goto read_status;
+ }
+
ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events);
if (parent)
pm_runtime_put(parent);