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authorVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>2014-08-03 13:24:05 +0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-08-05 09:40:41 +0400
commit6174bac8c7ff73a86ae9a967d1c9cadc478023ae (patch)
treea5ac87e70111d42797dc6aa68eb61e3a4cfa6177 /drivers/cpufreq
parentb00fc6ec1f24f9d7af9b8988b6a198186eb3408c (diff)
downloadlinux-6174bac8c7ff73a86ae9a967d1c9cadc478023ae.tar.xz
powerpc/cpufreq: Add pr_warn() on OPAL firmware failures
Cpufreq depends on platform firmware to implement PStates. In case of platform firmware failure, cpufreq should not panic host kernel with BUG_ON(). Less severe pr_warn() will suffice. Add firmware_has_feature(FW_FEATURE_OPALv3) check to skip probing for device-tree on non-powernv platforms. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> CC: <stable@vger.kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/powernv-cpufreq.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index bb1d08dc8cc8..379c0837f5a9 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -28,6 +28,7 @@
#include <linux/of.h>
#include <asm/cputhreads.h>
+#include <asm/firmware.h>
#include <asm/reg.h>
#include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */
@@ -98,7 +99,11 @@ static int init_powernv_pstates(void)
return -ENODEV;
}
- WARN_ON(len_ids != len_freqs);
+ if (len_ids != len_freqs) {
+ pr_warn("Entries in ibm,pstate-ids and "
+ "ibm,pstate-frequencies-mhz does not match\n");
+ }
+
nr_pstates = min(len_ids, len_freqs) / sizeof(u32);
if (!nr_pstates) {
pr_warn("No PStates found\n");
@@ -131,7 +136,12 @@ static unsigned int pstate_id_to_freq(int pstate_id)
int i;
i = powernv_pstate_info.max - pstate_id;
- BUG_ON(i >= powernv_pstate_info.nr_pstates || i < 0);
+ if (i >= powernv_pstate_info.nr_pstates || i < 0) {
+ pr_warn("PState id %d outside of PState table, "
+ "reporting nominal id %d instead\n",
+ pstate_id, powernv_pstate_info.nominal);
+ i = powernv_pstate_info.max - powernv_pstate_info.nominal;
+ }
return powernv_freqs[i].frequency;
}
@@ -321,6 +331,10 @@ static int __init powernv_cpufreq_init(void)
{
int rc = 0;
+ /* Don't probe on pseries (guest) platforms */
+ if (!firmware_has_feature(FW_FEATURE_OPALv3))
+ return -ENODEV;
+
/* Discover pstates from device tree and init */
rc = init_powernv_pstates();
if (rc) {