[3.16.y-ckt stable] Patch "powercap / RAPL: fix BIOS lock check" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    powercap / RAPL: fix BIOS lock check

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt23.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 1c0639acade2b51c395df7bfcb77fa0b2534bb39 Mon Sep 17 00:00:00 2001
From: Prarit Bhargava <prarit at redhat.com>
Date: Wed, 9 Dec 2015 08:31:12 -0500
Subject: powercap / RAPL: fix BIOS lock check

commit 79a21dbfae3cd40d5a801778071a9967b79c2c20 upstream.

Intel RAPL initialized on several systems where the BIOS lock bit (msr
0x610, bit 63) was set.  This occured because the return value of
rapl_read_data_raw() was being checked, rather than the value of the variable
passed in, locked.

This patch properly implments the rapl_read_data_raw() call to check the
variable locked, and now the Intel RAPL driver outputs the warning:

	intel_rapl: RAPL package 0 domain package locked by BIOS

and does not initialize for the package.

Signed-off-by: Prarit Bhargava <prarit at redhat.com>
Acked-by: Jacob Pan <jacob.jun.pan at linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/powercap/intel_rapl.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/powercap/intel_rapl.c b/drivers/powercap/intel_rapl.c
index a362dcc20ec0..ccb6768a352b 100644
--- a/drivers/powercap/intel_rapl.c
+++ b/drivers/powercap/intel_rapl.c
@@ -1191,10 +1191,13 @@ static int rapl_detect_domains(struct rapl_package *rp, int cpu)

 	for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
 		/* check if the domain is locked by BIOS */
-		if (rapl_read_data_raw(rd, FW_LOCK, false, &locked)) {
+		ret = rapl_read_data_raw(rd, FW_LOCK, false, &locked);
+		if (ret)
+			return ret;
+		if (locked) {
 			pr_info("RAPL package %d domain %s locked by BIOS\n",
 				rp->id, rd->name);
-				rd->state |= DOMAIN_STATE_BIOS_LOCKED;
+			rd->state |= DOMAIN_STATE_BIOS_LOCKED;
 		}
 	}