Re: [PATCH] cpufreq: sparc-us2e: fix frequency table index copy-paste error

[Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>]

On 8/28/2026 3:56 PM, Xueqin Luo wrote:
> In us2e_freq_cpu_init(), the last three writes to the frequency table
> all use index [2] instead of [2], [3], [4] respectively.  This is a

Nit: Should it be that "the last two frequency writes both use index
[2] instead of [3] and [4] respectively, and the terminator uses [3]
instead of [5]." ?


> copy-paste error where the index was not incremented, causing the
> divider-6 and divider-8 entries to overwrite the already-written
> divider-4 entry.
> 
> As a result, only three frequency steps (div 1, 2, and 8) are actually
> available to the cpufreq core, while the intended dividers 4 and 6 are

If the core passes the array index (2) to ->target_index(), and
index_to_divisor(2) is 4. so the real available div is 1,2,4?


> silently lost.  The struct us2e_freq_percpu_info::table[6] has room for
> 5 entries plus a terminator, matching the 5 hardware dividers.
> 
> Fix the indices so all five frequency steps are correctly populated:
> table[0]=div1, table[1]=div2, table[2]=div4, table[3]=div6,
> table[4]=div8, table[5]=TABLE_END.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Xueqin Luo <luoxueqin@kylinos.cn>
> ---
>   drivers/cpufreq/sparc-us2e-cpufreq.c | 11 +++++------
>   1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cpufreq/sparc-us2e-cpufreq.c b/drivers/cpufreq/sparc-us2e-cpufreq.c
> index a68706406b88..5cda391ad03b 100644
> --- a/drivers/cpufreq/sparc-us2e-cpufreq.c
> +++ b/drivers/cpufreq/sparc-us2e-cpufreq.c
> @@ -282,12 +282,11 @@ static int us2e_freq_cpu_init(struct cpufreq_policy *policy)
>   	table[1].frequency = clock_tick / 2;
>   	table[2].driver_data = 2;
>   	table[2].frequency = clock_tick / 4;
> -	table[2].driver_data = 3;
> -	table[2].frequency = clock_tick / 6;
> -	table[2].driver_data = 4;
> -	table[2].frequency = clock_tick / 8;
> -	table[2].driver_data = 5;
> -	table[3].frequency = CPUFREQ_TABLE_END;
> +	table[3].driver_data = 3;
> +	table[3].frequency = clock_tick / 6;
> +	table[4].driver_data = 4;
> +	table[4].frequency = clock_tick / 8;
> +	table[5].frequency = CPUFREQ_TABLE_END;
>   
>   	policy->cpuinfo.transition_latency = 0;
>   	policy->cur = clock_tick;


-- 
Thx and BRs,
Zhongqiu Han