Warning coming during boot because the boot freq set by bootloader
gets filtered out due to big freq steps while creating freq_table.
Fix this by setting closest higher frequency from freq_table.
Warning:
cpufreq: cpufreq_online: CPU0: Running at unlisted freq
cpufreq: cpufreq_online: CPU0: Unlisted initial frequency changed
These warning messages also come during hotplug online of non-boot
CPU's while exiting from 'Suspend-to-RAM'. This happens because
during exit from 'Suspend-to-RAM', some time is taken to restore
last software requested CPU frequency written in register before
entering suspend.
And who does this restoration ?
To fix this, adding online hook to wait till the
current frequency becomes equal or close to the last requested
frequency.
Fixes: df320f89359c ("cpufreq: Add Tegra194 cpufreq driver")
Signed-off-by: Sumit Gupta <sumitg@xxxxxxxxxx>
---
drivers/cpufreq/tegra194-cpufreq.c | 86 ++++++++++++++++++++++++++++++++++----
1 file changed, 79 insertions(+), 7 deletions(-)
diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c
index d250e49..cc28b1e3 100644
--- a/drivers/cpufreq/tegra194-cpufreq.c
+++ b/drivers/cpufreq/tegra194-cpufreq.c
@@ -7,6 +7,7 @@
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
@@ -21,7 +22,6 @@
#define KHZ 1000
#define REF_CLK_MHZ 408 /* 408 MHz */
#define US_DELAY 500
-#define US_DELAY_MIN 2
#define CPUFREQ_TBL_STEP_HZ (50 * KHZ * KHZ)
#define MAX_CNT ~0U
@@ -249,17 +249,22 @@ static unsigned int tegra194_get_speed(u32 cpu)
static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
{
struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
- u32 cpu;
+ u32 cpu = policy->cpu;
+ int ret;
u32 cl;
- smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
+ if (!cpu_online(cpu))
Not required to check this.
OK.
+ return -EINVAL;
+
+ ret = smp_call_function_single(cpu, get_cpu_cluster, &cl, true);
+ if (ret) {
Same as in the other patch.
Got.
+ pr_err("cpufreq: Failed to get cluster for CPU%d\n", cpu);
+ return ret;
+ }
if (cl >= data->num_clusters)
return -EINVAL;
- /* boot freq */
- policy->cur = tegra194_get_speed_common(policy->cpu, US_DELAY_MIN);
-
/* set same policy for all cpus in a cluster */
for (cpu = (cl * 2); cpu < ((cl + 1) * 2); cpu++)
cpumask_set_cpu(cpu, policy->cpus);
@@ -267,7 +272,23 @@ static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
policy->freq_table = data->tables[cl];
policy->cpuinfo.transition_latency = TEGRA_CPUFREQ_TRANSITION_LATENCY;
- return 0;
+ policy->cur = tegra194_get_speed_common(policy->cpu, US_DELAY);
+
+ ret = cpufreq_table_validate_and_sort(policy);
+ if (ret)
+ return ret;
+
+ /* Are we running at unknown frequency ? */
+ ret = cpufreq_frequency_table_get_index(policy, policy->cur);
+ if (ret == -EINVAL) {
+ ret = __cpufreq_driver_target(policy, policy->cur - 1,
+ CPUFREQ_RELATION_L);
+ if (ret)
+ return ret;
+ policy->cur = tegra194_get_speed_common(policy->cpu, US_DELAY);
cpufreq-core will do this anyway, you don't need to do it.
Got.
+ }
+
+ return ret;
}
I wonder if I should change the pr_warn() in cpufreq-core to pr_info()
instead, will that help you guys ? Will that still be a problem ? This
is exactly same as what we do there.
Yes, this will also work. Then we don't need the current patch.
You want me to send a patch with change from pr_warn to pr_info?
static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
@@ -285,6 +306,55 @@ static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
return 0;
}
+static int tegra194_cpufreq_online(struct cpufreq_policy *policy)
+{
+ unsigned int interm_freq, last_set_freq;
+ struct cpufreq_frequency_table *pos;
+ u64 ndiv;
+ int ret;
+
+ if (!cpu_online(policy->cpu))
+ return -EINVAL;
+
+ /* get ndiv for the last frequency request from software */
+ ret = smp_call_function_single(policy->cpu, get_cpu_ndiv, &ndiv, true);
+ if (ret) {
+ pr_err("cpufreq: Failed to get ndiv for CPU%d\n", policy->cpu);
+ return ret;
+ }
+
+ cpufreq_for_each_valid_entry(pos, policy->freq_table) {
+ if (pos->driver_data == ndiv) {
+ last_set_freq = pos->frequency;
+ break;
+ }
+ }
+
+ policy->cur = tegra194_get_speed_common(policy->cpu, US_DELAY);
+ interm_freq = policy->cur;
+
+ /*
+ * It takes some time to restore the previous frequency while
+ * turning-on non-boot cores during exit from SC7(Suspend-to-RAM).
+ * So, wait till it reaches the previous value and timeout if the
+ * time taken to reach requested freq is >100ms
+ */
+ ret = read_poll_timeout(tegra194_get_speed_common, policy->cur,
+ abs(policy->cur - last_set_freq) <= 115200, 0,
+ 100 * USEC_PER_MSEC, false, policy->cpu,
+ US_DELAY);
The firmware does this update ? Why do we need to wait for this ? I
was actually suggesting an empty tegra194_cpufreq_online() routine
here.
> --
viresh
