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authorTomas Winkler <tomas.winkler@intel.com>2012-08-06 15:23:55 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-16 09:40:28 -0700
commit9a123f19832702753805afe0e93db26799b91b07 (patch)
treeef70961cad7389f2ea2bddf89dc11d507effe90a /drivers/misc
parent07b509b7943e5594f3f228e5b62a49cf6a033709 (diff)
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 <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/mei/main.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index b0903bd44bf..86b73e59626 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -906,6 +906,27 @@ static struct miscdevice mei_misc_device = {
};
/**
+ * 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, &reg);
+ /* 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
*
* @pdev: PCI device structure
@@ -920,6 +941,12 @@ 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;