From: Jean Delvare <jdelvare@xxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit c0f5eeed0f4cef4f05b74883a7160e7edde58b6a upstream. 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 <jdelvare@xxxxxxx> Link: http://lkml.kernel.org/r/20140224093927.7659dd9d@endymion.delvare Reviewed-by: Alan Cox <alan@xxxxxxxxxxxxxxx> Cc: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx> Cc: Doug Thompson <dougthompson@xxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- 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 80a963d64e58..c67fb4d707d3 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) { -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html