This is a note to let you know that I've just added the patch titled pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts 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: pci-hotplug-pnv-php-disable-surprise-hotplug-capability-on-conflicts.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 303529d6ef1293513c2c73c9ab86489eebb37d08 Mon Sep 17 00:00:00 2001 From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> Date: Thu, 16 Feb 2017 10:22:33 +1100 Subject: pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> commit 303529d6ef1293513c2c73c9ab86489eebb37d08 upstream. The root port or PCIe switch downstream port might have been associated with driver other than pnv-php. The MSI or MSIx might also have been enabled by that driver (e.g. pcieport_drv). Attempt to enable MSI incurs below backtrace: PowerPC PowerNV PCI Hotplug Driver version: 0.1 ------------[ cut here ]------------ WARNING: CPU: 19 PID: 1004 at drivers/pci/msi.c:1071 \ __pci_enable_msi_range+0x84/0x4e0 NIP [c000000000665c34] __pci_enable_msi_range+0x84/0x4e0 LR [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0 Call Trace: [c000000384d67600] [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0 [c000000384d676e0] [d00000000aa31b04] pnv_php_register+0x564/0x5a0 [pnv_php] [c000000384d677c0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php] [c000000384d678a0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php] [c000000384d67980] [d00000000aa31dfc] pnv_php_init+0x60/0x98 [pnv_php] [c000000384d679f0] [c00000000000cfdc] do_one_initcall+0x6c/0x1d0 [c000000384d67ab0] [c000000000b92354] do_init_module+0x94/0x254 [c000000384d67b40] [c00000000019719c] load_module+0x258c/0x2c60 [c000000384d67d30] [c000000000197bb0] SyS_finit_module+0xf0/0x170 [c000000384d67e30] [c00000000000b184] system_call+0x38/0xe0 This fixes the issue by skipping enabling the surprise hotplug capability if the MSI or MSIx on the PCI slot's upstream port has been enabled by other driver. Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> Reviewed-by: Andrew Donnellan <andrew.donnellan@xxxxxxxxxxx> Tested-by: Vaibhav Jain <vaibhav@xxxxxxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/hotplug/pnv_php.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -799,6 +799,14 @@ static void pnv_php_enable_irq(struct pn struct pci_dev *pdev = php_slot->pdev; int irq, ret; + /* + * The MSI/MSIx interrupt might have been occupied by other + * drivers. Don't populate the surprise hotplug capability + * in that case. + */ + if (pci_dev_msi_enabled(pdev)) + return; + ret = pci_enable_device(pdev); if (ret) { dev_warn(&pdev->dev, "Error %d enabling device\n", ret); 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