4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Gavin Shan <gws...@linux.vnet.ibm.com>
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 <hankmax0...@gmail.com>
Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
Tested-by: Willie Liauw <will...@supermicro.com.tw>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/pci/hotplug/pnv_php.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- 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
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;
