mei: me: do not load the driver if the FW doesn't support MEI interface
commit 5e6533a6f52f1a8283b2f818f5828be99a417dd6 upstream.
NM and SPS FW types that may run on ME device on server platforms
do not have valid MEI/HECI interface and driver should not
be bound to it as this might lead to system hung.
In practice not all BIOSes effectively hide such devices from the
OS and in some cases it is not possible.
We determine FW type by examining Host FW status registers in order to
unbind the driver.
In this patch we are adding check for ME on Cougar Point, Lynx Point
Devices
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mei/hw-me-regs.h b/drivers/misc/mei/hw-me-regs.h
index 66f411a..cabc043 100644
--- a/drivers/misc/mei/hw-me-regs.h
+++ b/drivers/misc/mei/hw-me-regs.h
@@ -115,6 +115,11 @@
#define MEI_DEV_ID_LPT_HR 0x8CBA /* Lynx Point H Refresh */
#define MEI_DEV_ID_WPT_LP 0x9CBA /* Wildcat Point LP */
+
+/* Host Firmware Status Registers in PCI Config Space */
+#define PCI_CFG_HFS_1 0x40
+#define PCI_CFG_HFS_2 0x48
+
/*
* MEI HW Section
*/