6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mike Tipton quic_mdtipton@quicinc.com
[ Upstream commit 6c9bb86922728c7a4cceb99f131e00dd87514f20 ]
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 Reviewed-by: Peng Fan peng.fan@nxp.com Reviewed-by: Cristian Marussi cristian.marussi@arm.com Reviewed-by: Sudeep Holla sudeep.holla@arm.com Tested-by: Cristian Marussi cristian.marussi@arm.com Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/cpufreq/scmi-cpufreq.c | 36 +++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c index e4989764efe2a..6ff77003a96ea 100644 --- a/drivers/cpufreq/scmi-cpufreq.c +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -299,6 +299,40 @@ static struct cpufreq_driver scmi_cpufreq_driver = { .register_em = scmi_cpufreq_register_em, };
+static bool scmi_dev_used_by_cpus(struct device *scmi_dev) +{ + struct device_node *scmi_np = dev_of_node(scmi_dev); + struct device_node *cpu_np, *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; + + cpu_np = dev_of_node(cpu_dev); + + np = of_parse_phandle(cpu_np, "clocks", 0); + of_node_put(np); + + if (np == scmi_np) + return true; + + idx = of_property_match_string(cpu_np, "power-domain-names", "perf"); + np = of_parse_phandle(cpu_np, "power-domains", idx); + of_node_put(np); + + if (np == scmi_np) + return true; + } + + return false; +} + static int scmi_cpufreq_probe(struct scmi_device *sdev) { int ret; @@ -307,7 +341,7 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev)
handle = sdev->handle;
- if (!handle) + if (!handle || !scmi_dev_used_by_cpus(dev)) return -ENODEV;
perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph);