| Message ID | 20170727100128.26818-1-waldemarx.rymarkiewicz@intel.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Delegated to: | Rafael Wysocki |
| Headers | show |
Hi,
This patch fixes problem with setting opp shared cpus bitmask on
hotplugable systems. See patch commit message for details.
CHANGLOG:
v5 0-day reported issue fixed
v4 Added Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> + use pr_err
instead dev_err for missing opp node phandle.
v3 Acked-by: Viresh Kumar added
v2 Abandon v1 as it was not good enough. Still check all possible CPUs as in
original code, but don't check device struct. Instead check device_node
directly in DT.
v1 [PATCH] PM / OPP: Don't check not plugged in CPUs to avoid error
Avoid error by checking all present cpus instead possible cpus.
Thanks,
/Waldek
Waldemar Rymarkiewicz (1):
PM / OPP: Fix get sharing cpus when hotplug is used
drivers/base/power/opp/of.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)
On Thursday, July 27, 2017 12:01:17 PM 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> Applied, thanks!
diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c index 57eec1c..fba6d2e 100644 --- a/drivers/base/power/opp/of.c +++ b/drivers/base/power/opp/of.c @@ -248,15 +248,22 @@ void dev_pm_opp_of_remove_table(struct device *dev) } EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table); -/* Returns opp descriptor node for a device, caller must do of_node_put() */ -struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev) +/* Returns opp descriptor node for a device node, caller must + * do of_node_put() */ +static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np) { /* * There should be only ONE phandle present in "operating-points-v2" * property. */ - return of_parse_phandle(dev->of_node, "operating-points-v2", 0); + return of_parse_phandle(np, "operating-points-v2", 0); +} + +/* Returns opp descriptor node for a device, caller must do of_node_put() */ +struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev) +{ + return _opp_of_get_opp_desc_node(dev->of_node); } EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node); @@ -572,8 +579,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table); int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) { - struct device_node *np, *tmp_np; - struct device *tcpu_dev; + struct device_node *np, *tmp_np, *cpu_np; int cpu, ret = 0; /* Get OPP descriptor node */ @@ -593,19 +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", - __func__); + pr_err("%pOF: Couldn't find opp node\n", cpu_np); ret = -ENOENT; goto put_cpu_node; }