From a2f6985332d2564e443d9d889ce70f39b3293d09 Mon Sep 17 00:00:00 2001 From: Tomas Winkler Date: Mon, 6 Aug 2012 15:23:55 +0300 Subject: [PATCH] mei: add mei_quirk_probe function The main purpose of this function is to exclude ME devices without support for MEI/HECI interface from binding Currently affected systems are C600/X79 based servers that expose PCI device even though it doesn't supported ME Interface. MEI driver accessing such nonfunctional device can corrupt the system. Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/main.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c index 09233020886..7422c765284 100644 --- a/drivers/misc/mei/main.c +++ b/drivers/misc/mei/main.c @@ -924,6 +924,27 @@ static struct miscdevice mei_misc_device = { .minor = MISC_DYNAMIC_MINOR, }; +/** + * mei_quirk_probe - probe for devices that doesn't valid ME interface + * @pdev: PCI device structure + * @ent: entry into pci_device_table + * + * returns true if ME Interface is valid, false otherwise + */ +static bool __devinit mei_quirk_probe(struct pci_dev *pdev, + const struct pci_device_id *ent) +{ + u32 reg; + if (ent->device == MEI_DEV_ID_PBG_1) { + pci_read_config_dword(pdev, 0x48, ®); + /* make sure that bit 9 is up and bit 10 is down */ + if ((reg & 0x600) == 0x200) { + dev_info(&pdev->dev, "Device doesn't have valid ME Interface\n"); + return false; + } + } + return true; +} /** * mei_probe - Device Initialization Routine * @@ -939,6 +960,12 @@ static int __devinit mei_probe(struct pci_dev *pdev, int err; mutex_lock(&mei_mutex); + + if (!mei_quirk_probe(pdev, ent)) { + err = -ENODEV; + goto end; + } + if (mei_device) { err = -EEXIST; goto end; -- 2.46.0