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authorKeith Busch <keith.busch@intel.com>2017-08-01 03:11:52 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-09-27 14:43:19 +0200
commitba5cc8b6cb3fb3e667c638842847e6930a7b9817 (patch)
tree677512cd0f9341c0724a2578187e9538e654c3e9 /drivers/pci
parent8061afaf1269a5988705fe8167a8c07d3b891028 (diff)
PCI: pciehp: Report power fault only once until we clear it
commit 7612b3b28c0b900dcbcdf5e9b9747cc20a1e2455 upstream. When a power fault occurs, the power controller sets Power Fault Detected in the Slot Status register, and pciehp_isr() queues an INT_POWER_FAULT event to handle it. It also clears Power Fault Detected, but since nothing has yet changed to correct the power fault, the power controller will likely set it again immediately, which may cause an infinite loop when pcie_isr() rechecks Slot Status. Fix that by masking off Power Fault Detected from new events if the driver hasn't seen the power fault clear from the previous handling attempt. Fixes: fad214b0aa72 ("PCI: pciehp: Process all hotplug events before looking for new ones") Signed-off-by: Keith Busch <keith.busch@intel.com> [bhelgaas: changelog, pull test out and add comment] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Mayurkumar Patel <mayurkumar.patel@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 026830a138ae..e5d5ce9e3010 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -586,6 +586,14 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
events = 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;
+
if (!events)
return IRQ_NONE;