[PATCH 3.16.y-ckt 061/128] powercap / RAPL: fix BIOS lock check

From: Luis Henriques
Date: Sun Jan 24 2016 - 17:26:42 EST

3.16.7-ckt23 -stable review patch. If anyone has any objections, please let me know.


From: Prarit Bhargava <prarit@xxxxxxxxxx>

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@xxxxxxxxxx>
Acked-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
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);