Commit f17b3e44320b ("cpufreq: qcom-hw: Use
devm_platform_ioremap_resource() to simplify code") introduces
a regression on platforms using the driver, by failing to initialise
a policy, when one is created post hotplug.
When all the CPUs of a policy are hoptplugged out, the call to .exit()
and later to devm_iounmap() does not release the memory region that was
requested during devm_platform_ioremap_resource(). Therefore,
a subsequent call to .init() will result in the following error, which
will prevent a new policy to be initialised:
[ 3395.915416] CPU4: shutdown
[ 3395.938185] psci: CPU4 killed (polled 0 ms)
[ 3399.071424] CPU5: shutdown
[ 3399.094316] psci: CPU5 killed (polled 0 ms)
[ 3402.139358] CPU6: shutdown
[ 3402.161705] psci: CPU6 killed (polled 0 ms)
[ 3404.742939] CPU7: shutdown
[ 3404.765592] psci: CPU7 killed (polled 0 ms)
[ 3411.492274] Detected VIPT I-cache on CPU4
[ 3411.492337] GICv3: CPU4: found redistributor 400 region 0:0x0000000017ae0000
[ 3411.492448] CPU4: Booted secondary processor 0x0000000400 [0x516f802d]
[ 3411.503654] qcom-cpufreq-hw 17d43000.cpufreq: can't request region for resource [mem 0x17d45800-0x17d46bff]
With that being said, the original code was tricky and skipping memory
region request intentionally to hide this issue. The true cause is that
those devm_xxx() device managed functions shouldn't be used for cpufreq
init/exit hooks, because &pdev->dev is alive across the hooks and will
not trigger auto resource free-up. Let's drop the use of device managed
functions and manually allocate/free resources, so that the issue can be
fixed properly.
Fixes: f17b3e44320b ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code")
Suggested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
---
Changes for v2:
- Move kzalloc() around to respect the original sequence which makes
the local variables use reasonable.
drivers/cpufreq/qcom-cpufreq-hw.c | 40 ++++++++++++++++++++++++-------
1 file changed, 32 insertions(+), 8 deletions(-)
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 9ed5341dc515..2726e77c9e5a 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -32,6 +32,7 @@ struct qcom_cpufreq_soc_data {
struct qcom_cpufreq_data {
void __iomem *base;
+ struct resource *res;
const struct qcom_cpufreq_soc_data *soc_data;
};
@@ -280,6 +281,7 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
struct of_phandle_args args;
struct device_node *cpu_np;
struct device *cpu_dev;
+ struct resource *res;
void __iomem *base;
struct qcom_cpufreq_data *data;
int ret, index;
@@ -303,18 +305,33 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
index = args.args[0];
- base = devm_platform_ioremap_resource(pdev, index);
- if (IS_ERR(base))
- return PTR_ERR(base);
+ res = platform_get_resource(pdev, IORESOURCE_MEM, index);
+ if (!res) {
+ dev_err(dev, "failed to get mem resource %d\n", index);
+ return -ENODEV;
+ }
+
+ if (!request_mem_region(res->start, resource_size(res), res->name)) {
+ dev_err(dev, "failed to request resource %pR\n", res);
+ return -EBUSY;
+ }
- data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ base = ioremap(res->start, resource_size(res));
+ if (IS_ERR(base)) {
+ dev_err(dev, "failed to map resource %pR\n", res);
+ ret = PTR_ERR(base);
+ goto release_region;
+ }
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
- goto error;
+ goto unmap_base;
}
data->soc_data = of_device_get_match_data(&pdev->dev);
data->base = base;
+ data->res = res;
/* HW should be in enabled state to proceed */
if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) {
@@ -349,7 +366,11 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
return 0;
error:
- devm_iounmap(dev, base);
+ kfree(data);
+unmap_base:
+ iounmap(data->base);
+release_region:
+ release_mem_region(res->start, resource_size(res));
return ret;
}
@@ -357,12 +378,15 @@ static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
{
struct device *cpu_dev = get_cpu_device(policy->cpu);
struct qcom_cpufreq_data *data = policy->driver_data;
- struct platform_device *pdev = cpufreq_get_driver_data();
+ struct resource *res = data->res;
+ void __iomem *base = data->base;
dev_pm_opp_remove_all_dynamic(cpu_dev);
dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
kfree(policy->freq_table);
- devm_iounmap(&pdev->dev, data->base);
+ kfree(data);
+ iounmap(base);
+ release_mem_region(res->start, resource_size(res));
return 0;
}
--
2.17.1
