diff options
| author | Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> | 2014-08-03 14:54:05 +0530 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-08-05 15:40:41 +1000 |
| commit | 6174bac8c7ff73a86ae9a967d1c9cadc478023ae (patch) | |
| tree | a5ac87e70111d42797dc6aa68eb61e3a4cfa6177 /drivers/cpufreq/powernv-cpufreq.c | |
| parent | b00fc6ec1f24f9d7af9b8988b6a198186eb3408c (diff) | |
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/powernv-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/powernv-cpufreq.c | 18 |
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) { |