]> git.baikalelectronics.ru Git - kernel.git/commit
cpufreq: longhaul: Revert transition_delay_us to 200 ms
authorViresh Kumar <viresh.kumar@linaro.org>
Thu, 7 Dec 2017 09:45:19 +0000 (15:15 +0530)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 13 Dec 2017 00:37:09 +0000 (01:37 +0100)
commite5908803e374878a004b4c00d399b816f8580525
tree04b4a57d8da8270ac750f0a7c018b65c8bbc878e
parent59c67513a2d282d8c1ff80df69b97c9c6de62004
cpufreq: longhaul: Revert transition_delay_us to 200 ms

The commit ff637461cf3e ("cpufreq: Cap the default transition delay
value to 10 ms") caused a regression on EPIA-M min-ITX computer where
shutdown or reboot hangs occasionally with a print message like:

longhaul: Warning: Timeout while waiting for idle PCI bus
cpufreq: __target_index: Failed to change cpu frequency: -16

This probably happens because the cpufreq governor tries to change the
frequency of the CPU faster than allowed by the hardware.

Before the above commit, the default transition delay was set to 200 ms
for a transition_latency of 200000 ns. Lets revert back to that
transition delay value to fix it. Note that several other transition
delay values were tested like 20 ms and 30 ms and none of them have
resolved system hang issue completely.

Fixes: ff637461cf3e (cpufreq: Cap the default transition delay value to 10 ms)
Reported-by: Meelis Roos <mroos@linux.ee>
Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/cpufreq/longhaul.c