patch "mei: me: do not load the driver if the FW doesn't support MEI" added to char-misc tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    mei: me: do not load the driver if the FW doesn't support MEI

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 5e6533a6f52f1a8283b2f818f5828be99a417dd6 Mon Sep 17 00:00:00 2001
From: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Date: Tue, 25 Mar 2014 21:25:18 +0200
Subject: mei: me: do not load the driver if the FW doesn't support MEI
 interface

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

Cc: stable <stable@xxxxxxxxxxxxxxx> # 3.10+
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Tested-by: Nikola Ciprich <nikola.ciprich@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/misc/mei/hw-me-regs.h |  5 +++++
 drivers/misc/mei/pci-me.c     | 30 +++++++++++++++++++++++-------
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/mei/hw-me-regs.h b/drivers/misc/mei/hw-me-regs.h
index 66f411a6e8ea..cabc04383685 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
  */
diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
index 1c8fd3a3e135..95889e2e31ff 100644
--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -97,15 +97,31 @@ static bool mei_me_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;
-		}
+	/* Cougar Point || Patsburg */
+	if (ent->device == MEI_DEV_ID_CPT_1 ||
+	    ent->device == MEI_DEV_ID_PBG_1) {
+		pci_read_config_dword(pdev, PCI_CFG_HFS_2, &reg);
+		/* make sure that bit 9 (NM) is up and bit 10 (DM) is down */
+		if ((reg & 0x600) == 0x200)
+			goto no_mei;
 	}
+
+	/* Lynx Point */
+	if (ent->device == MEI_DEV_ID_LPT_H  ||
+	    ent->device == MEI_DEV_ID_LPT_W  ||
+	    ent->device == MEI_DEV_ID_LPT_HR) {
+		/* Read ME FW Status check for SPS Firmware */
+		pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
+		/* if bits [19:16] = 15, running SPS Firmware */
+		if ((reg & 0xf0000) == 0xf0000)
+			goto no_mei;
+	}
+
 	return true;
+
+no_mei:
+	dev_info(&pdev->dev, "Device doesn't have valid ME Interface\n");
+	return false;
 }
 /**
  * mei_probe - Device Initialization Routine
-- 
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