2014-04-28 16:18:49

by Tim Gardner

Subject: [PATCH 3.15-rc3] cpufreq: ppc-corenet-cpufreq: Fix __udivdi3 modpost error

bfa709bc823fc32ee8dd5220d1711b46078235d8 (cpufreq: powerpc: add cpufreq
transition latency for FSL e500mc SoCs) introduced a modpost error:

ERROR: "__udivdi3" [drivers/cpufreq/ppc-corenet-cpufreq.ko] undefined!
make[1]: *** [__modpost] Error 1

Fix this by avoiding 64 bit integer division.

gcc version 4.8.2

Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Viresh Kumar <[email protected]>
Cc: Zhuoyu Zhang <[email protected]>
Signed-off-by: Tim Gardner <[email protected]>
---
drivers/cpufreq/ppc-corenet-cpufreq.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
index a1ca3dd..0af618a 100644
--- a/drivers/cpufreq/ppc-corenet-cpufreq.c
+++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
@@ -138,6 +138,7 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
struct cpufreq_frequency_table *table;
struct cpu_data *data;
unsigned int cpu = policy->cpu;
+ u64 transition_latency_hz;

np = of_get_cpu_node(cpu, NULL);
if (!np)
@@ -205,8 +206,10 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
for_each_cpu(i, per_cpu(cpu_mask, cpu))
per_cpu(cpu_data, i) = data;

+ transition_latency_hz = 12ULL * NSEC_PER_SEC;
policy->cpuinfo.transition_latency =
- (12ULL * NSEC_PER_SEC) / fsl_get_sys_freq();
+ do_div(transition_latency_hz, fsl_get_sys_freq());
+
of_node_put(np);

return 0;
--
1.7.9.5

2014-06-04 20:33:17

by Ed Swarthout

Subject: [PATCH] cpufreq: ppc-corenet-cpu-freq: do_div use quotient

6712d2931933ada259b82f06c03a855b19937074 (cpufreq:
ppc-corenet-cpufreq: Fix __udivdi3 modpost error) used the remainder
from do_div instead of the quotient. Fix that and add one to ensure
minimum is met.

Signed-off-by: Ed Swarthout <[email protected]>
---
drivers/cpufreq/ppc-corenet-cpufreq.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
index 0af618a..3607070 100644
--- a/drivers/cpufreq/ppc-corenet-cpufreq.c
+++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
@@ -138,7 +138,7 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
struct cpufreq_frequency_table *table;
struct cpu_data *data;
unsigned int cpu = policy->cpu;
- u64 transition_latency_hz;
+ u64 u64temp;

np = of_get_cpu_node(cpu, NULL);
if (!np)
@@ -206,9 +206,10 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
for_each_cpu(i, per_cpu(cpu_mask, cpu))
per_cpu(cpu_data, i) = data;

- transition_latency_hz = 12ULL * NSEC_PER_SEC;
- policy->cpuinfo.transition_latency =
- do_div(transition_latency_hz, fsl_get_sys_freq());
+ /* Minimum transition latency is 12 platform clocks */
+ u64temp = 12ULL * NSEC_PER_SEC;
+ do_div(u64temp, fsl_get_sys_freq());
+ policy->cpuinfo.transition_latency = u64temp + 1;

of_node_put(np);

--
1.9.1

2014-06-06 14:03:43

by Tim Gardner

Subject: Re: [PATCH] cpufreq: ppc-corenet-cpu-freq: do_div use quotient

On 06/04/2014 02:32 PM, Ed Swarthout wrote:
> 6712d2931933ada259b82f06c03a855b19937074 (cpufreq:
> ppc-corenet-cpufreq: Fix __udivdi3 modpost error) used the remainder
> from do_div instead of the quotient. Fix that and add one to ensure
> minimum is met.
>
> Signed-off-by: Ed Swarthout <[email protected]>
> ---
> drivers/cpufreq/ppc-corenet-cpufreq.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
> index 0af618a..3607070 100644
> --- a/drivers/cpufreq/ppc-corenet-cpufreq.c
> +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
> @@ -138,7 +138,7 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
> struct cpufreq_frequency_table *table;
> struct cpu_data *data;
> unsigned int cpu = policy->cpu;
> - u64 transition_latency_hz;
> + u64 u64temp;
>
> np = of_get_cpu_node(cpu, NULL);
> if (!np)
> @@ -206,9 +206,10 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
> for_each_cpu(i, per_cpu(cpu_mask, cpu))
> per_cpu(cpu_data, i) = data;
>
> - transition_latency_hz = 12ULL * NSEC_PER_SEC;
> - policy->cpuinfo.transition_latency =
> - do_div(transition_latency_hz, fsl_get_sys_freq());
> + /* Minimum transition latency is 12 platform clocks */
> + u64temp = 12ULL * NSEC_PER_SEC;
> + do_div(u64temp, fsl_get_sys_freq());
> + policy->cpuinfo.transition_latency = u64temp + 1;
>
> of_node_put(np);
>
>

Whoops, what was I thinking ? You should also add "Cc:
[email protected] # 3.15+" since this patch will likely miss 3.15
final.

Acked-by: Tim Gardner <[email protected]>

--
Tim Gardner [email protected]