On Mon 2020-07-20 17:37:50, Greg Kroah-Hartman wrote:
> From: Finley Xiao <finley.xiao@xxxxxxxxxxxxxx>
>
> commit 371a3bc79c11b707d7a1b7a2c938dc3cc042fffb upstream.
>
> The function cpu_power_to_freq is used to find a frequency and set the
> cooling device to consume at most the power to be converted. For example,
> if the power to be converted is 80mW, and the em table is as follow.
> struct em_cap_state table[] = {
> /* KHz mW */
> { 1008000, 36, 0 },
> { 1200000, 49, 0 },
> { 1296000, 59, 0 },
> { 1416000, 72, 0 },
> { 1512000, 86, 0 },
> };
> The target frequency should be 1416000KHz, not 1512000KHz.
>
> Fixes: 349d39dc5739 ("thermal: cpu_cooling: merge frequency and power tables")
Wow, this is completely different from the upstream patch. There the
loops goes down, not up. The code does not match the changelog here.
> --- a/drivers/thermal/cpu_cooling.c
> +++ b/drivers/thermal/cpu_cooling.c
> @@ -278,11 +278,11 @@ static u32 cpu_power_to_freq(struct cpuf
> int i;
> struct freq_table *freq_table = cpufreq_cdev->freq_table;
>
> - for (i = 1; i <= cpufreq_cdev->max_level; i++)
> - if (power > freq_table[i].power)
> + for (i = 0; i < cpufreq_cdev->max_level; i++)
> + if (power >= freq_table[i].power)
> break;
>
> - return freq_table[i - 1].frequency;
> + return freq_table[i].frequency;
> }
Something is very wrong here, if table is sorted like described in the
changelog, it will always break at i==0 or i==1... not working at all
in the old or the new version.
Best regards,
Pavel
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Attachment:
signature.asc
Description: PGP signature
