[PATCH AUTOSEL 4.19 021/177] tools/power/cpupower: Fix initializer override in hsw_ext_cstates

[PATCH AUTOSEL 4.19 021/177] tools/power/cpupower: Fix initializer override in hsw_ext_cstates

[Sasha Levin]

From: Nathan Chancellor <natechancellor@gmail.com>

[ Upstream commit 7e5705c635ecfccde559ebbbe1eaf05b5cc60529 ]

When building cpupower with clang, the following warning appears:

 utils/idle_monitor/hsw_ext_idle.c:42:16: warning: initializer overrides
 prior initialization of this subobject [-Winitializer-overrides]
                 .desc                   = N_("Processor Package C2"),
                                              ^~~~~~~~~~~~~~~~~~~~~~
 ./utils/helpers/helpers.h:25:33: note: expanded from macro 'N_'
 #define N_(String) gettext_noop(String)
                                 ^~~~~~
 ./utils/helpers/helpers.h:23:30: note: expanded from macro
 'gettext_noop'
 #define gettext_noop(String) String
                              ^~~~~~
 utils/idle_monitor/hsw_ext_idle.c:41:16: note: previous initialization
 is here
                 .desc                   = N_("Processor Package C9"),
                                              ^~~~~~~~~~~~~~~~~~~~~~
 ./utils/helpers/helpers.h:25:33: note: expanded from macro 'N_'
 #define N_(String) gettext_noop(String)
                                 ^~~~~~
 ./utils/helpers/helpers.h:23:30: note: expanded from macro
 'gettext_noop'
 #define gettext_noop(String) String
                             ^~~~~~
 1 warning generated.

This appears to be a copy and paste or merge mistake because the name
and id fields both have PC9 in them, not PC2. Remove the second
assignment to fix the warning.

Fixes: 7ee767b69b68 ("cpupower: Add Haswell family 0x45 specific idle monitor to show PC8,9,10 states")
Link: https://github.com/ClangBuiltLinux/linux/issues/718
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/power/cpupower/utils/idle_monitor/hsw_ext_idle.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/power/cpupower/utils/idle_monitor/hsw_ext_idle.c b/tools/power/cpupower/utils/idle_monitor/hsw_ext_idle.c
index f794d6bbb7e9f..3e4ff4a1cdf4b 100644
--- a/tools/power/cpupower/utils/idle_monitor/hsw_ext_idle.c
+++ b/tools/power/cpupower/utils/idle_monitor/hsw_ext_idle.c
@@ -40,7 +40,6 @@ static cstate_t hsw_ext_cstates[HSW_EXT_CSTATE_COUNT] = {
 	{
 		.name			= "PC9",
 		.desc			= N_("Processor Package C9"),
-		.desc			= N_("Processor Package C2"),
 		.id			= PC9,
 		.range			= RANGE_PACKAGE,
 		.get_count_percent	= hsw_ext_get_count_percent,
-- 
2.20.1

[PATCH AUTOSEL 4.19 144/177] cpufreq: Register drivers only after CPU devices have been registered

[Sasha Levin]

From: Viresh Kumar <viresh.kumar@linaro.org>

[ Upstream commit 46770be0cf94149ca48be87719bda1d951066644 ]

The cpufreq core heavily depends on the availability of the struct
device for CPUs and if they aren't available at the time cpufreq driver
is registered, we will never succeed in making cpufreq work.

This happens due to following sequence of events:

- cpufreq_register_driver()
  - subsys_interface_register()
  - return 0; //successful registration of driver

... at a later point of time

- register_cpu();
  - device_register();
    - bus_probe_device();
      - sif->add_dev();
	- cpufreq_add_dev();
	  - get_cpu_device(); //FAILS
  - per_cpu(cpu_sys_devices, num) = &cpu->dev; //used by get_cpu_device()
  - return 0; //CPU registered successfully

Because the per-cpu variable cpu_sys_devices is set only after the CPU
device is regsitered, cpufreq will never be able to get it when
cpufreq_add_dev() is called.

This patch avoids this failure by making sure device structure of at
least CPU0 is available when the cpufreq driver is registered, else
return -EPROBE_DEFER.

Reported-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/cpufreq.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 9d8d64f706e06..e35c397b1259f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2480,6 +2480,13 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
 	if (cpufreq_disabled())
 		return -ENODEV;
 
+	/*
+	 * The cpufreq core depends heavily on the availability of device
+	 * structure, make sure they are available before proceeding further.
+	 */
+	if (!get_cpu_device(0))
+		return -EPROBE_DEFER;
+
 	if (!driver_data || !driver_data->verify || !driver_data->init ||
 	    !(driver_data->setpolicy || driver_data->target_index ||
 		    driver_data->target) ||
-- 
2.20.1