| Message ID | 20250421195206.3736128-1-quic_mdtipton@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] cpufreq: scmi: Skip SCMI devices that aren't used by the CPUs | expand |
On Mon, Apr 21, 2025 at 12:52:06PM -0700, Mike Tipton wrote: >Currently, all SCMI devices with performance domains attempt to register >a cpufreq driver, even if their performance domains aren't used to >control the CPUs. The cpufreq framework only supports registering a >single driver, so only the first device will succeed. And if that device >isn't used for the CPUs, then cpufreq will scale the wrong domains. > >To avoid this, return early from scmi_cpufreq_probe() if the probing >SCMI device isn't referenced by the CPU device phandles. > >This keeps the existing assumption that all CPUs are controlled by a >single SCMI device. > >Signed-off-by: Mike Tipton <quic_mdtipton@quicinc.com> >--- >Changes in v2: >- Return -ENODEV instead of 0 for irrelevant devices. >- Link to v1: https://lore.kernel.org/all/20250411212941.1275572-1-quic_mdtipton@quicinc.com/ > > drivers/cpufreq/scmi-cpufreq.c | 28 +++++++++++++++++++++++++++- > 1 file changed, 27 insertions(+), 1 deletion(-) > >diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c >index 944e899eb1be..b558f210c342 100644 >--- a/drivers/cpufreq/scmi-cpufreq.c >+++ b/drivers/cpufreq/scmi-cpufreq.c >@@ -393,6 +393,32 @@ static struct cpufreq_driver scmi_cpufreq_driver = { > .set_boost = cpufreq_boost_set_sw, > }; > >+static bool scmi_dev_used_by_cpus(struct device *scmi_dev) >+{ >+ struct device_node *scmi_np = scmi_dev->of_node; Nitpick: dev_of_node(scmi_dev->of_node) ? >+ struct device_node *np; >+ struct device *cpu_dev; >+ int cpu, idx; if (!scmi_np) return false; >+ >+ for_each_possible_cpu(cpu) { >+ cpu_dev = get_cpu_device(cpu); >+ if (!cpu_dev) >+ continue; >+ >+ np = cpu_dev->of_node; dev_of_node(cpu_dev); >+ >+ if (of_parse_phandle(np, "clocks", 0) == scmi_np) >+ return true; >+ >+ idx = of_property_match_string(np, "power-domain-names", "perf"); >+ >+ if (of_parse_phandle(np, "power-domains", idx) == scmi_np) >+ return true; >+ } >+ >+ return false; >+} >+ > static int scmi_cpufreq_probe(struct scmi_device *sdev) > { > int ret; >@@ -401,7 +427,7 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev) > > handle = sdev->handle; > >- if (!handle) >+ if (!handle || !scmi_dev_used_by_cpus(dev)) > return -ENODEV; > With the minor comments addressed, LGTM: Reviewed-by: Peng Fan <peng.fan@nxp.com> Regards, Peng
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c index 944e899eb1be..b558f210c342 100644 --- a/drivers/cpufreq/scmi-cpufreq.c +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -393,6 +393,32 @@ static struct cpufreq_driver scmi_cpufreq_driver = { .set_boost = cpufreq_boost_set_sw, }; +static bool scmi_dev_used_by_cpus(struct device *scmi_dev) +{ + struct device_node *scmi_np = scmi_dev->of_node; + struct device_node *np; + struct device *cpu_dev; + int cpu, idx; + + for_each_possible_cpu(cpu) { + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) + continue; + + np = cpu_dev->of_node; + + if (of_parse_phandle(np, "clocks", 0) == scmi_np) + return true; + + idx = of_property_match_string(np, "power-domain-names", "perf"); + + if (of_parse_phandle(np, "power-domains", idx) == scmi_np) + return true; + } + + return false; +} + static int scmi_cpufreq_probe(struct scmi_device *sdev) { int ret; @@ -401,7 +427,7 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev) handle = sdev->handle; - if (!handle) + if (!handle || !scmi_dev_used_by_cpus(dev)) return -ENODEV; scmi_cpufreq_driver.driver_data = sdev;
Currently, all SCMI devices with performance domains attempt to register a cpufreq driver, even if their performance domains aren't used to control the CPUs. The cpufreq framework only supports registering a single driver, so only the first device will succeed. And if that device isn't used for the CPUs, then cpufreq will scale the wrong domains. To avoid this, return early from scmi_cpufreq_probe() if the probing SCMI device isn't referenced by the CPU device phandles. This keeps the existing assumption that all CPUs are controlled by a single SCMI device. Signed-off-by: Mike Tipton <quic_mdtipton@quicinc.com> --- Changes in v2: - Return -ENODEV instead of 0 for irrelevant devices. - Link to v1: https://lore.kernel.org/all/20250411212941.1275572-1-quic_mdtipton@quicinc.com/ drivers/cpufreq/scmi-cpufreq.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-)