linux.git/drivers/base/power/opp/core.c, branch v4.9

PM / OPP: avoid maybe-uninitialized warning

2016-09-16T22:58:00+00:00

When CONFIG_OPTIMIZE_INLINING is set and we are building with -Wmaybe-uninitialized
enabled, we can get a warning for the opp core driver:

drivers/base/power/opp/core.c: In function 'dev_pm_opp_set_rate':
drivers/base/power/opp/core.c:560:8: warning: 'ou_volt_min' may be used uninitialized in this function [-Wmaybe-uninitialized]

This has only now appeared as a result of commit 797da5598f3a ("PM / devfreq:
Add COMPILE_TEST for build coverage"), which makes the driver visible in
some configurations that didn't have it before.

The warning is a false positive that I got with gcc-6.1.1, but there is
a simple workaround in removing the local variables that we get warnings
for (all three are affected depending on the configuration). This also
makes the code easier to read.

Signed-off-by: Arnd Bergmann 
Reviewed-by: Stephen Boyd 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

PM / OPP: optimize dev_pm_opp_set_rate() performance a bit

2016-07-28T21:54:16+00:00

In dev_pm_opp_set_rate(), _find_opp_table() is called 4 times: once by
_get_opp_clk(), once by dev_pm_opp_set_rate() itself, and twice by
dev_pm_opp_find_freq_ceil(). If there are several opp_tables in the
system, three times of opp table finding is a big waste. This patch
reduced the call of _find_opp_table() to twice.

Signed-off-by: Jisheng Zhang 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

Merge back new material for v4.7.

2016-05-06T20:05:16+00:00

PM / OPP: Move CONFIG_OF dependent code in a separate file

2016-05-06T11:22:49+00:00

Recently, a few issues were noticed in the code where CONFIG_OF wasn't
consistently used for many routines. The core file is big enough now and
ifdef hackery makes it less readable.

Move OF-specific code to another file and compile that only if CONFIG_OF
is enabled.

Compile-tested:
- For ARM (exynos) with CONFIG_OF enabled
- For X86 with CONFIG_OF disabled (have to enable CONFIG_PM_OPP separately)

No functional changes.

Signed-off-by: Viresh Kumar 
Tested-by: Sudeep Holla 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Remove useless check

2016-05-04T23:42:19+00:00

Regulators are optional for devices using OPPs and the OPP core
shouldn't be printing any errors for such missing regulators.

It was fine before the commit 0c717d0f9cb4, but that failed to update
this part of the code to remove an 'always true' check and an extra
unwanted print message.

Fix that now.

Fixes: 0c717d0f9cb4 (PM / OPP: Initialize regulator pointer to an error value)
Reported-by: Marc Gonzalez 
Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: add non-OF versions of dev_pm_opp_{cpumask_, }remove_table

2016-05-04T23:38:44+00:00

Functions dev_pm_opp_of_{cpumask_,}remove_table removes/frees all the
static OPP entries associated with the device and/or all cpus(in case
of cpumask) that are created from DT.

However the OPP entries are populated reading from the firmware or some
different method using dev_pm_opp_add are marked dynamic and can't be
removed using above functions.

This patch adds non DT/OF versions of dev_pm_opp_{cpumask_,}remove_table
to support the above mentioned usecase.

This is in preparation to make use of the same in scpi-cpufreq.c

Signed-off-by: Sudeep Holla 
Acked-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Rename structures for clarity

2016-02-21T13:24:35+00:00

Stephen pointed out recently, that few structures always confuse him as
they aren't named properly. And this patch tries to address that:

Names are updated as:
- device_opp or dev_opp -> opp_table
- dev_opp_list -> opp_tables
- dev_opp_list_lock -> opp_table_lock
- device_list_opp -> opp_device (it was never a list, but a structure)
- list_dev -> opp_dev
- And similar changes in comments and function names as well.

This also fixes checkpatch warnings that were generated with this patch.

No functional changes.

Suggested-by: Stephen Boyd 
Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Fix incorrect comments

2016-02-21T13:24:04+00:00

Some comments were just copy/pasted from other sections and don't match
to the routines they were added for. Fix them.

Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Initialize regulator pointer to an error value

2016-02-16T12:12:41+00:00

We are currently required to do two checks for regulator pointer:
IS_ERR() and IS_NULL().

And multiple instances are reported, about both of these not being used
consistently and so resulting in crashes.

Fix that by initializing regulator pointer with an error value and
checking it only against an error.

This makes code more consistent and more efficient.

Fixes: 7d34d56ef334 (PM / OPP: Disable OPPs that aren't supported by the regulator)
Reported-and-tested-by: Jon Hunter 
Reported-and-tested-by: Tony Lindgren 
Reported-and-tested-by: Guenter Roeck 
Signed-off-by: Viresh Kumar 
[ rjw: Initialize to -ENXIO ]
Signed-off-by: Rafael J. Wysocki

PM / OPP: Initialize u_volt_min/max to a valid value

2016-02-15T21:55:35+00:00

We kept u_volt_min/max initialized to 0, when only the target voltage is
present in DT, instead of the target/min/max triplet.

This didn't go well with the regulator framework, as on few calls the
min voltage was set to target and max was set to 0 and so resulted in a
kernel crash like below:

kernel BUG at ../drivers/regulator/core.c:216!

[] (regulator_check_voltage) from [] (regulator_set_voltage_unlocked+0x58/0x230)
[] (regulator_set_voltage_unlocked) from [] (regulator_set_voltage+0x28/0x54)
[] (regulator_set_voltage) from [] (_set_opp_voltage+0x30/0x98)
[] (_set_opp_voltage) from [] (dev_pm_opp_set_rate+0xf0/0x28c)
[] (dev_pm_opp_set_rate) from [] (__cpufreq_driver_target+0x184/0x2b4)
[] (__cpufreq_driver_target) from [] (dbs_check_cpu+0x1b0/0x1f4)
[] (dbs_check_cpu) from [] (cpufreq_governor_dbs+0x324/0x5c4)
[] (cpufreq_governor_dbs) from [] (__cpufreq_governor+0xe4/0x1ec)
[] (__cpufreq_governor) from [] (cpufreq_init_policy+0x64/0x8c)
[] (cpufreq_init_policy) from [] (cpufreq_online+0x2fc/0x708)
[] (cpufreq_online) from [] (subsys_interface_register+0x94/0xd8)
[] (subsys_interface_register) from [] (cpufreq_register_driver+0x14c/0x19c)
[] (cpufreq_register_driver) from [] (dt_cpufreq_probe+0x70/0xec)
[] (dt_cpufreq_probe) from [] (platform_drv_probe+0x4c/0xb0)
[] (platform_drv_probe) from [] (driver_probe_device+0x214/0x2c0)
[] (driver_probe_device) from [] (__driver_attach+0x8c/0x90)
[] (__driver_attach) from [] (bus_for_each_dev+0x68/0x9c)
[] (bus_for_each_dev) from [] (bus_add_driver+0x1a0/0x218)
[] (bus_add_driver) from [] (driver_register+0x78/0xf8)
[] (driver_register) from [] (do_one_initcall+0x90/0x1d8)
[] (do_one_initcall) from [] (kernel_init_freeable+0x15c/0x1fc)
[] (kernel_init_freeable) from [] (kernel_init+0x8/0xf0)
[] (kernel_init) from [] (ret_from_fork+0x14/0x3c)
Code: e1550004 baffffeb e3a00000 e8bd8070 (e7f001f2)

Fix that by initializing u_volt_min/max to the target voltage in such cases.

Reported-and-tested-by: Krzysztof Kozlowski 
Fixes: 274659029c9d (PM / OPP: Add support to parse "operating-points-v2" bindings)
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki