From c0f5eeed0f4cef4f05b74883a7160e7edde58b6a Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 24 Feb 2014 09:39:27 +0100 Subject: [PATCH] i7core_edac: Fix PCI device reference count The reference count changes done by pci_get_device can be a little misleading when the usage diverges from the most common scheme. The reference count of the device passed as the last parameter is always decreased, even if the function returns no new device. So if we are going to try alternative device IDs, we must manually increment the device reference count before each retry. If we don't, we end up decreasing the reference count, and after a few modprobe/rmmod cycles the PCI devices will vanish. In other words and as Alan put it: without this fix the EDAC code corrupts the PCI device list. This fixes kernel bug #50491: https://bugzilla.kernel.org/show_bug.cgi?id=50491 Signed-off-by: Jean Delvare Link: http://lkml.kernel.org/r/20140224093927.7659dd9d@endymion.delvare Reviewed-by: Alan Cox Cc: Mauro Carvalho Chehab Cc: Doug Thompson Cc: stable@vger.kernel.org Signed-off-by: Borislav Petkov --- drivers/edac/i7core_edac.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/edac/i7core_edac.c b/drivers/edac/i7core_edac.c index 87533ca..d871275 100644 --- a/drivers/edac/i7core_edac.c +++ b/drivers/edac/i7core_edac.c @@ -1334,14 +1334,19 @@ static int i7core_get_onedevice(struct pci_dev **prev, * is at addr 8086:2c40, instead of 8086:2c41. So, we need * to probe for the alternate address in case of failure */ - if (dev_descr->dev_id == PCI_DEVICE_ID_INTEL_I7_NONCORE && !pdev) + if (dev_descr->dev_id == PCI_DEVICE_ID_INTEL_I7_NONCORE && !pdev) { + pci_dev_get(*prev); /* pci_get_device will put it */ pdev = pci_get_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_I7_NONCORE_ALT, *prev); + } - if (dev_descr->dev_id == PCI_DEVICE_ID_INTEL_LYNNFIELD_NONCORE && !pdev) + if (dev_descr->dev_id == PCI_DEVICE_ID_INTEL_LYNNFIELD_NONCORE && + !pdev) { + pci_dev_get(*prev); /* pci_get_device will put it */ pdev = pci_get_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_LYNNFIELD_NONCORE_ALT, *prev); + } if (!pdev) { if (*prev) { -- 2.7.4