Messages in this thread Patch in this message | | | From | Stefan Wiehler <> | Subject | [PATCH v3 RESEND] arm: topology: Consider clock-frequency property from parent /cpus node | Date | Fri, 21 Jul 2023 11:40:01 +0200 |
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If the clock-frequency property is not set in the cpu node but in the parent /cpus node, the following warning is emitted:
/cpus/cpu@X missing clock-frequency property
The devicetree specification in section 3.8 however specifies that "properties that have identical values across cpu nodes may be placed in the /cpus node instead. A client program must first examine a specific cpu node, but if an expected property is not found then it should look at the parent /cpus node."
Signed-off-by: Stefan Wiehler <stefan.wiehler@nokia.com> --- - Refactored /cpus node lookup - Add missing node refcount decrement via of_node_put(); of_get_property() does not need it - Track lifetime of /cpus node separately --- arch/arm/kernel/topology.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index ef0058de432b..32fc1c8d9d11 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -85,15 +85,24 @@ static bool cap_from_dt = true; static void __init parse_dt_topology(void) { const struct cpu_efficiency *cpu_eff; - struct device_node *cn = NULL; + struct device_node *pcn = NULL, *cn = NULL; unsigned long min_capacity = ULONG_MAX; unsigned long max_capacity = 0; unsigned long capacity = 0; int cpu = 0; + const __be32 *common_rate; + int common_rate_len; __cpu_capacity = kcalloc(nr_cpu_ids, sizeof(*__cpu_capacity), GFP_NOWAIT); + pcn = of_find_node_by_path("/cpus"); + if (!pcn) { + pr_err("missing CPU root device node\n"); + return; + } + common_rate = of_get_property(pcn, "clock-frequency", &common_rate_len); + for_each_possible_cpu(cpu) { const __be32 *rate; int len; @@ -121,8 +130,12 @@ static void __init parse_dt_topology(void) rate = of_get_property(cn, "clock-frequency", &len); if (!rate || len != 4) { - pr_err("%pOF missing clock-frequency property\n", cn); - continue; + if (common_rate && common_rate_len == 4) { + rate = common_rate; + } else { + pr_err("%pOF missing clock-frequency property\n", cn); + continue; + } } capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency; @@ -154,6 +167,8 @@ static void __init parse_dt_topology(void) if (cap_from_dt) topology_normalize_cpu_scale(); + + of_node_put(pcn); } /* -- 2.31.0
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