cpufreq: CPPC: Use transition_delay_us depending transition_latency
authorGeorge Cherian <george.cherian@cavium.com>
Fri, 23 Mar 2018 10:30:31 +0000 (03:30 -0700)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Fri, 30 Mar 2018 10:15:58 +0000 (12:15 +0200)
commit3d41386d556db9f720e00de3e11e45f39cb5071c
tree3b04b6dfe0445d3e13f2ba7da722011a6fec894a
parenta8b6966034ba88190eca397e2693b5bc16790517
cpufreq: CPPC: Use transition_delay_us depending transition_latency

With commit e948bc8fbee0 (cpufreq: Cap the default transition delay
value to 10 ms)  the cpufreq was not honouring the delay passed via
ACPI (PCCT). Due to which on ARM based platforms using CPPC the
cpufreq governor tries to change the frequency of CPUs faster than
expected.

This leads to continuous error messages like the following.
" ACPI CPPC: PCC check channel failed. Status=0 "

Earlier (without above commit) the default transition delay was
taken form the value passed from PCCT. Use the same value provided
by PCCT to set the transition_delay_us.

Fixes: e948bc8fbee0 (cpufreq: Cap the default transition delay value to 10 ms)
Signed-off-by: George Cherian <george.cherian@cavium.com>
Cc: 4.14+ <stable@vger.kernel.org> # 4.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/cpufreq/cppc_cpufreq.c