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cpufreq: qcom-hw: drop devm_xxx() calls from init/exit hooks

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Commit f17b3e4432 ("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.

Cc: v5.10+ <stable@vger.kernel.org> # v5.10+
Fixes: f17b3e4432 ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code")
Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Shawn Guo 2021-01-19 10:39:25 +08:00 committed by Viresh Kumar
parent 7114ebffd3
commit 67fc209b52
1 changed files with 32 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
drivers/cpufreq/qcom-cpufreq-hw.c
View File

@ -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;
}
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!request_mem_region(res->start, resource_size(res), res->name)) {
dev_err(dev, "failed to request resource %pR\n", res);
return -EBUSY;
}
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)) {
@ -355,7 +372,11 @@ 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;
}
@ -363,12 +384,15 @@ 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;
}