redonkable/remarkable-linux
redonkable/remarkable-linux
1
0
Fork 0
Code Releases Activity

intel_pstate: remove setting P state to MAX on init

Browse source 
Setting the P state of the core to max at init time is a hold over
from early implementation of intel_pstate where intel_pstate disabled
cpufreq and loaded VERY early in the boot sequence.  This was to
ensure that intel_pstate did not affect boot time. This in not needed
now that intel_pstate is a cpufreq driver.

Removing this covers the case where a CPU has gone through a manual
CPU offline/online cycle and the P state is set to MAX on init and the
CPU immediately goes idle.  Due to HW coordination the P state request
on the idle CPU will drag all cores to MAX P state until the load is
reevaluated when to core goes non-idle.

Reported-by: Patrick Marlier <patrick.marlier@gmail.com>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Dirk Brandewie 2014-05-08 12:57:24 -07:00 committed by Rafael J. Wysocki
parent 21855ff5bc
commit d40a63c45b
1 changed files with 1 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
drivers/cpufreq/intel_pstate.c
View file

@ -554,12 +554,7 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
if (pstate_funcs.get_vid)
pstate_funcs.get_vid(cpu);
/*
* goto max pstate so we don't slow up boot if we are built-in if we are
* a module we will take care of it during normal operation
*/
intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
}
static inline void intel_pstate_calc_busy(struct cpudata *cpu,
@ -704,11 +699,6 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
cpu = all_cpu_data[cpunum];
intel_pstate_get_cpu_pstates(cpu);
if (!cpu->pstate.current_pstate) {
all_cpu_data[cpunum] = NULL;
kfree(cpu);
return -ENODATA;
}
cpu->cpu = cpunum;
@ -719,7 +709,6 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
cpu->timer.expires = jiffies + HZ/100;
intel_pstate_busy_pid_reset(cpu);
intel_pstate_sample(cpu);
intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
add_timer_on(&cpu->timer, cpunum);