Messages in this thread | | | Date | Fri, 29 May 2020 17:00:57 +0530 | From | Sibi Sankar <> | Subject | Re: [PATCH v5 4/5] cpufreq: qcom: Update the bandwidth levels on frequency change |
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Hey Viresh, Thanks for taking time to review the series :)
On 2020-05-29 15:30, Viresh Kumar wrote: > On 28-05-20, 01:51, Sibi Sankar wrote: >> Add support to parse optional OPP table attached to the cpu node when >> the OPP bandwidth values are populated. This allows for scaling of >> DDR/L3 bandwidth levels with frequency change. >> >> Signed-off-by: Sibi Sankar <sibis@codeaurora.org> >> --- >> >> V5: >> * Use dev_pm_opp_adjust_voltage instead [Viresh] >> * Misc cleanup >> >> v4: >> * Split fast switch disable into another patch [Lukasz] >> >> drivers/cpufreq/qcom-cpufreq-hw.c | 77 >> ++++++++++++++++++++++++++++++- >> 1 file changed, 75 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c >> b/drivers/cpufreq/qcom-cpufreq-hw.c >> index fc92a8842e252..fbd73d106a3ae 100644 >> --- a/drivers/cpufreq/qcom-cpufreq-hw.c >> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c >> @@ -6,6 +6,7 @@ >> #include <linux/bitfield.h> >> #include <linux/cpufreq.h> >> #include <linux/init.h> >> +#include <linux/interconnect.h> >> #include <linux/kernel.h> >> #include <linux/module.h> >> #include <linux/of_address.h> >> @@ -31,6 +32,52 @@ >> static unsigned long cpu_hw_rate, xo_rate; >> static struct platform_device *global_pdev; >> >> +static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy, >> + unsigned long freq_khz) >> +{ >> + unsigned long freq_hz = freq_khz * 1000; >> + struct dev_pm_opp *opp; >> + struct device *dev; >> + int ret; >> + >> + dev = get_cpu_device(policy->cpu); >> + if (!dev) >> + return -ENODEV; >> + >> + opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true); >> + if (IS_ERR(opp)) >> + return PTR_ERR(opp); >> + >> + ret = dev_pm_opp_set_bw(dev, opp); >> + dev_pm_opp_put(opp); >> + return ret; >> +} >> + >> +static int qcom_cpufreq_update_opp(struct device *cpu_dev, >> + unsigned long freq_khz, >> + unsigned long volt) >> +{ >> + unsigned long freq_hz = freq_khz * 1000; >> + >> + if (dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt)) >> + return dev_pm_opp_add(cpu_dev, freq_hz, volt); > > What's going on here ? Why add OPP here ?
We update the voltage if opp were initially added as part of dev_pm_opp_of_add_table. However if the cpu node does not have an opp table associated with it, we do a opp_add_v1 instead.
> >> + >> + /* Enable the opp after voltage update */ >> + return dev_pm_opp_enable(cpu_dev, freq_hz); >> +} >> + >> +/* Check for optional interconnect paths on CPU0 */ >> +static int qcom_cpufreq_find_icc_paths(struct device *dev) >> +{ >> + struct device *cpu_dev; >> + >> + cpu_dev = get_cpu_device(0); >> + if (!cpu_dev) >> + return -EPROBE_DEFER; >> + >> + return dev_pm_opp_of_find_icc_paths(cpu_dev, NULL); >> +} >> + > > open code this into the probe routine.
sure
> >> static int qcom_cpufreq_hw_target_index(struct cpufreq_policy >> *policy, >> unsigned int index) >> { >> @@ -39,6 +86,8 @@ static int qcom_cpufreq_hw_target_index(struct >> cpufreq_policy *policy, >> >> writel_relaxed(index, perf_state_reg); >> >> + qcom_cpufreq_set_bw(policy, freq); >> + >> arch_set_freq_scale(policy->related_cpus, freq, >> policy->cpuinfo.max_freq); >> return 0; >> @@ -88,12 +137,30 @@ static int qcom_cpufreq_hw_read_lut(struct device >> *cpu_dev, >> { >> u32 data, src, lval, i, core_count, prev_freq = 0, freq; >> u32 volt; >> + u64 rate; >> struct cpufreq_frequency_table *table; >> + struct device_node *opp_table_np, *np; >> + int ret; >> >> table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL); >> if (!table) >> return -ENOMEM; >> >> + ret = dev_pm_opp_of_add_table(cpu_dev); >> + if (!ret) { >> + /* Disable all opps and cross-validate against LUT */ >> + opp_table_np = dev_pm_opp_of_get_opp_desc_node(cpu_dev); >> + for_each_available_child_of_node(opp_table_np, np) { >> + ret = of_property_read_u64(np, "opp-hz", &rate); > > No way, please use dev_pm_opp_find_freq_*() here instead to grab OPPs > one by one.
sure I'll use a dev_pm_opp_find_freq_ceil loop to do the same :P
> >> + if (!ret) >> + dev_pm_opp_disable(cpu_dev, rate); >> + } >> + of_node_put(opp_table_np); >> + } else if (ret != -ENODEV) { >> + dev_err(cpu_dev, "Invalid OPP table in Device tree\n"); >> + return ret; >> + } > > Rather put this in the if (ret) block and so the else part doesn't > need extra indentation.
https://patchwork.kernel.org/patch/11573905/
I'll need to enable fast_switch when the device does not have a opp-table associated with it or throw a error when an improper table is specified. If a table with bw values is specified, we disable fast switch and enable scaling.
> >> + >> for (i = 0; i < LUT_MAX_ENTRIES; i++) { >> data = readl_relaxed(base + REG_FREQ_LUT + >> i * LUT_ROW_SIZE); >> @@ -112,7 +179,7 @@ static int qcom_cpufreq_hw_read_lut(struct device >> *cpu_dev, >> >> if (freq != prev_freq && core_count != LUT_TURBO_IND) { >> table[i].frequency = freq; >> - dev_pm_opp_add(cpu_dev, freq * 1000, volt); >> + qcom_cpufreq_update_opp(cpu_dev, freq, volt); >> dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i, >> freq, core_count); >> } else if (core_count == LUT_TURBO_IND) { >> @@ -133,7 +200,8 @@ static int qcom_cpufreq_hw_read_lut(struct device >> *cpu_dev, >> if (prev->frequency == CPUFREQ_ENTRY_INVALID) { >> prev->frequency = prev_freq; >> prev->flags = CPUFREQ_BOOST_FREQ; >> - dev_pm_opp_add(cpu_dev, prev_freq * 1000, volt); >> + qcom_cpufreq_update_opp(cpu_dev, prev_freq, >> + volt); >> } >> >> break;
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