* Re: [PATCH v3 1/1] PM / OPP: Fix get sharing cpus when hotplug is used
[not found] <20170724160342.1879-1-waldemarx.rymarkiewicz@intel.com>
@ 2017-07-26 0:54 ` Stephen Boyd
2017-07-26 9:18 ` Waldemar Rymarkiewicz
2017-07-26 6:16 ` Viresh Kumar
1 sibling, 1 reply; 4+ messages in thread
From: Stephen Boyd @ 2017-07-26 0:54 UTC (permalink / raw)
To: Waldemar Rymarkiewicz, linux-pm
Cc: waldemar.rymarkiewicz, Viresh Kumar, Nishanth Menon
On 07/24/2017 09:03 AM, Waldemar Rymarkiewicz wrote:
> We fail dev_pm_opp_of_get_sharing_cpus() when possible cpu device does not
> exist. This can happen on platforms where not all possible CPUs are
> available at start up ie. hotplugged out. Cpu device is not registered in
> the system so we are not able to check struct device to set the sharing
> CPUs bitmask properly.
>
> Example (real use case):
> 2 physical MIPS cores, 4 VPE, cpu0/2 run Linux and cpu1/3 are not available
> for Linux at boot up. cpufreq-dt driver + opp v2 fail to register opp_table
> due to the fact there is no struct device for cpu1 (remains offline at
> bootup).
>
> To solve the bug, stop using device struct to check device_node. Instead
> get cpu device_node directly from device tree with of_get_cpu_node().
>
> Signed-off-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
One minor nit, but it's fine to change later as well.
> @@ -593,18 +599,18 @@ int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
> if (cpu == cpu_dev->id)
> continue;
>
> - tcpu_dev = get_cpu_device(cpu);
> - if (!tcpu_dev) {
> - dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
> + cpu_np = of_get_cpu_node(cpu, NULL);
> + if (!cpu_np) {
> + dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
> __func__, cpu);
> - ret = -ENODEV;
> + ret = -ENOENT;
> goto put_cpu_node;
> }
>
> /* Get OPP descriptor node */
> - tmp_np = dev_pm_opp_of_get_opp_desc_node(tcpu_dev);
> + tmp_np = _opp_of_get_opp_desc_node(cpu_np);
> if (!tmp_np) {
> - dev_err(tcpu_dev, "%s: Couldn't find opp node.\n",
> + dev_err(cpu_dev, "%s: Couldn't find opp node.\n",
I would remove the full-stop. And also use %pOF with cpu_np and pr_err()
instead of dev_err() here so that we print out the node that's missing
the OPP node pointer.
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v3 1/1] PM / OPP: Fix get sharing cpus when hotplug is used
[not found] <20170724160342.1879-1-waldemarx.rymarkiewicz@intel.com>
2017-07-26 0:54 ` [PATCH v3 1/1] PM / OPP: Fix get sharing cpus when hotplug is used Stephen Boyd
@ 2017-07-26 6:16 ` Viresh Kumar
2017-07-26 9:26 ` Waldemar Rymarkiewicz
1 sibling, 1 reply; 4+ messages in thread
From: Viresh Kumar @ 2017-07-26 6:16 UTC (permalink / raw)
To: Waldemar Rymarkiewicz, Rafael J. Wysocki
Cc: linux-pm, WaldemarRymarkiewiczwaldemar.rymarkiewicz, Viresh Kumar,
Nishanth Menon, Stephen Boyd
+Rafael,
On 24-07-17, 18:03, Waldemar Rymarkiewicz wrote:
> We fail dev_pm_opp_of_get_sharing_cpus() when possible cpu device does not
> exist. This can happen on platforms where not all possible CPUs are
> available at start up ie. hotplugged out. Cpu device is not registered in
> the system so we are not able to check struct device to set the sharing
> CPUs bitmask properly.
>
> Example (real use case):
> 2 physical MIPS cores, 4 VPE, cpu0/2 run Linux and cpu1/3 are not available
> for Linux at boot up. cpufreq-dt driver + opp v2 fail to register opp_table
> due to the fact there is no struct device for cpu1 (remains offline at
> bootup).
>
> To solve the bug, stop using device struct to check device_node. Instead
> get cpu device_node directly from device tree with of_get_cpu_node().
>
> Signed-off-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> drivers/base/power/opp/of.c | 28 +++++++++++++++++-----------
> 1 file changed, 17 insertions(+), 11 deletions(-)
@Waldemar: I don't see this series on patchwork [1]. Are you
subscribed for that list ?
--
viresh
[1] https://patchwork.kernel.org/project/linux-pm/list/
^ permalink raw reply [flat|nested] 4+ messages in thread