This is a note to let you know that I've just added the patch titled drivers/pci/hotplug: Handle presence detection change properly to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drivers-pci-hotplug-handle-presence-detection-change-properly.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d7d55536c6cd1f80295b6d7483ad0587b148bde4 Mon Sep 17 00:00:00 2001 From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> Date: Wed, 11 Jan 2017 11:50:06 +1100 Subject: drivers/pci/hotplug: Handle presence detection change properly From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> 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 <hankmax0000@xxxxxxxxx> Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> Tested-by: Willie Liauw <williel@xxxxxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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; Patches currently in stable-queue which might be from gwshan@xxxxxxxxxxxxxxxxxx are queue-4.9/pci-hotplug-pnv-php-remove-warn_on-in-pnv_php_put_slot.patch queue-4.9/pci-hotplug-pnv-php-disable-surprise-hotplug-capability-on-conflicts.patch queue-4.9/drivers-pci-hotplug-handle-presence-detection-change-properly.patch queue-4.9/drivers-pci-hotplug-fix-initial-state-for-empty-slot.patch