From 2fd62929c88f4cd0e4a8d920b509504249ff67aa Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Tue, 1 Aug 2017 03:11:52 -0400 Subject: [PATCH] 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 [bhelgaas: changelog, pull test out and add comment] Signed-off-by: Bjorn Helgaas Cc: Mayurkumar Patel Signed-off-by: Greg Kroah-Hartman --- drivers/pci/hotplug/pciehp_hpc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index b57fc6d..d08dfc8 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; -- 2.7.4