[PATCH] cpufreq: powernv: Check negative value returned by cpufreq_table_find_index_dl()

[Shilpasri G Bhat]

This patch fixes the below Coverity warning:

*** CID 182816:  Memory - illegal accesses  (NEGATIVE_RETURNS)
/drivers/cpufreq/powernv-cpufreq.c: 1008 in powernv_fast_switch()
1002                                            unsigned int target_freq)
1003     {
1004            int index;
1005            struct powernv_smp_call_data freq_data;
1006
1007            index = cpufreq_table_find_index_dl(policy, target_freq);
>>>     CID 182816:  Memory - illegal accesses  (NEGATIVE_RETURNS)
>>>     Using variable "index" as an index to array "powernv_freqs".
1008            freq_data.pstate_id = powernv_freqs[index].driver_data;
1009            freq_data.gpstate_id = powernv_freqs[index].driver_data;
1010            set_pstate(&freq_data);
1011
1012            return powernv_freqs[index].frequency;
1013     }

Signed-off-by: Shilpasri G Bhat <shilpa.b...@linux.vnet.ibm.com>
---
 drivers/cpufreq/powernv-cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/powernv-cpufreq.c 
b/drivers/cpufreq/powernv-cpufreq.c
index 29cdec1..69edfe9 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -1005,6 +1005,9 @@ static unsigned int powernv_fast_switch(struct 
cpufreq_policy *policy,
        struct powernv_smp_call_data freq_data;
 
        index = cpufreq_table_find_index_dl(policy, target_freq);
+       if (unlikely(index < 0))
+               index = get_nominal_index();
+
        freq_data.pstate_id = powernv_freqs[index].driver_data;
        freq_data.gpstate_id = powernv_freqs[index].driver_data;
        set_pstate(&freq_data);
-- 
1.8.3.1