Messages in this thread | | | Date | Fri, 15 Apr 2022 14:24:08 +0200 | Subject | Re: [PATCH V3 11/15] cpufreq: mediatek: Link CCI device to CPU | From | AngeloGioacchino Del Regno <> |
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Il 15/04/22 07:59, Rex-BC Chen ha scritto: > From: Jia-Wei Chang <jia-wei.chang@mediatek.com> > > In some MediaTek SoCs, like MT8183, CPU and CCI share the same power > supplies. Cpufreq needs to check if CCI devfreq exists and wait until > CCI devfreq ready before scaling frequency. > > Before CCI devfreq is ready, we record the voltage when booting to > kernel and use the max(cpu target voltage, booting voltage) to > prevent cpufreq adjust to the lower voltage which will cause the CCI > crash because of high frequency and low voltage. > > - Add is_ccifreq_ready() to link CCI device to CPI, and CPU will start > DVFS when CCI is ready. > - Add platform data for MT8183. > > Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com> > Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
I am enthusiast to see that the solution that I've proposed was welcome!
I only have one nit on this patch, check below:
> --- > drivers/cpufreq/mediatek-cpufreq.c | 80 +++++++++++++++++++++++++++++- > 1 file changed, 79 insertions(+), 1 deletion(-) > > diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c > index d4c00237e862..dd3f739fede1 100644 > --- a/drivers/cpufreq/mediatek-cpufreq.c > +++ b/drivers/cpufreq/mediatek-cpufreq.c
..snip..
> @@ -225,6 +251,14 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy, > vproc = dev_pm_opp_get_voltage(opp); > dev_pm_opp_put(opp); > > + /* > + * If MediaTek cci is supported but is not ready, we will use the value > + * of max(target cpu voltage, booting voltage) to prevent high freqeuncy > + * low voltage crash. > + */ > + if (info->soc_data->ccifreq_supported && !is_ccifreq_ready(info)) > + vproc = max(vproc, info->vproc_on_boot); > + > /* > * If the new voltage or the intermediate voltage is higher than the > * current voltage, scale up voltage first.
..snip..
> @@ -423,6 +484,13 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu) > if (ret) > goto out_disable_mux_clock; > > + info->vproc_on_boot = regulator_get_voltage(info->proc_reg);
This result is used only if we use ccifreq, so this should be enclosed in an if condition: this will spare us some (yes, small) time on devices that don't use it.
if (info->soc_data->ccifreq_supported) { info->vproc_on_boot = regulator_get_voltage(info->proc_reg); if (info->vproc_on_boot < 0) { dev_err(.... goto .. } }
P.S.: While at it, since the maximum width is 100 columns, the dev_err() call fits, so don't break that line!
After the requested change:
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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