From 7250ff7dd18b7a7a650af4079bbf940f20fd4253 Mon Sep 17 00:00:00 2001 From: Tomas Winkler Date: Tue, 2 Dec 2014 00:29:53 +0200 Subject: [PATCH] mei: add mei_quirk_probe function commit 9a123f19832702753805afe0e93db26799b91b07 upstream. 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. [Backported to 3.2: files were moved] Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/staging/mei/main.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/staging/mei/main.c b/drivers/staging/mei/main.c index eb05c36f45d41..44ed7a859ecdf 100644 --- a/drivers/staging/mei/main.c +++ b/drivers/staging/mei/main.c @@ -105,6 +105,27 @@ MODULE_DEVICE_TABLE(pci, mei_pci_tbl); static DEFINE_MUTEX(mei_mutex); +/** + * 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 * @@ -120,6 +141,12 @@ 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; -- 2.47.2