From 633992b3d9078224e395d67ed429f575d7a94aec Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Wed, 11 Jan 2017 11:50:06 +1100 Subject: [PATCH] drivers/pci/hotplug: Handle presence detection change properly BugLink: http://bugs.launchpad.net/bugs/1673118 commit d7d55536c6cd1f80295b6d7483ad0587b148bde4 upstream. The surprise hotplug is driven by interrupt in PowerNV PCI hotplug driver. In the interrupt handler, pnv_php_interrupt(), we bail when pnv_pci_get_presence_state() returns zero wrongly. It causes the presence change event is always ignored incorrectly. This fixes the issue by bailing on error (non-zero value) returned from pnv_pci_get_presence_state(). Fixes: 360aebd85a4 ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Reported-by: Hank Chang Signed-off-by: Gavin Shan Tested-by: Willie Liauw Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Tim Gardner --- drivers/pci/hotplug/pnv_php.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 99b05338b4bc..e1c29909e7d3 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -713,8 +713,12 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data) added = !!(lsts & PCI_EXP_LNKSTA_DLLLA); } else if (sts & PCI_EXP_SLTSTA_PDC) { ret = pnv_pci_get_presence_state(php_slot->id, &presence); - if (!ret) + if (ret) { + dev_warn(&pdev->dev, "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n", + php_slot->name, ret, sts); return IRQ_HANDLED; + } + added = !!(presence == OPAL_PCI_SLOT_PRESENT); } else { return IRQ_NONE; -- 2.39.5