drivers/pci/hotplug: Handle presence detection change properly

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: 360aebd85a ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
Cc: stable@vger.kernel.org #v4.9+
Reported-by: Hank Chang <hankmax0000@gmail.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: Willie Liauw <williel@supermicro.com.tw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Gavin Shan 2017-01-11 11:50:06 +11:00 committed by Michael Ellerman
parent 5b102782c7
commit d7d55536c6

View file

@ -707,8 +707,12 @@ 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;