From: Kenji Kaneshige Date: Tue, 3 Feb 2009 06:06:13 +0000 (+0900) Subject: PCI: pciehp: fix possible endless loop in pcie_isr X-Git-Tag: firefly_0821_release~14994^2~70 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=81b840cd27e3ee9af67b6e05a4847868f74fce69;p=firefly-linux-kernel-4.4.55.git PCI: pciehp: fix possible endless loop in pcie_isr Fix possible endless loop in pcie_isr. Currently, pcie_isr() (interrupt service routine of pciehp) can end up in an endless loop if the Slot Status register is set again immediately after being cleared. According to the past discussion (see below URL) this case can happen if the power fault detected bit is set during handling. http://sourceforge.net/mailarchive/message.php?msg_id=20051130135409.A14918%40unix-os.sc.intel.com Signed-off-by: Kenji Kaneshige Signed-off-by: Jesse Barnes --- diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 7a16c6897bb9..c1a312f24060 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -672,10 +672,11 @@ static irqreturn_t pcie_isr(int irq, void *dev_id) detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC); + detected &= ~intr_loc; intr_loc |= detected; if (!intr_loc) return IRQ_NONE; - if (detected && pciehp_writew(ctrl, PCI_EXP_SLTSTA, detected)) { + if (detected && pciehp_writew(ctrl, PCI_EXP_SLTSTA, intr_loc)) { ctrl_err(ctrl, "%s: Cannot write to SLOTSTATUS\n", __func__); return IRQ_NONE;