From 303529d6ef1293513c2c73c9ab86489eebb37d08 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 16 Feb 2017 10:22:33 +1100 Subject: [PATCH] pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts 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. Cc: # v4.9+ Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Signed-off-by: Gavin Shan Reviewed-by: Andrew Donnellan Tested-by: Vaibhav Jain Signed-off-by: Michael Ellerman --- drivers/pci/hotplug/pnv_php.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index da1bbf3..6d36b76 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -826,6 +826,14 @@ static void pnv_php_enable_irq(struct pnv_php_slot *php_slot) 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); -- 2.7.4