Revision 3221e55b72359c44ed75afbcf707710af5bc2d59 authored by Srivatsa S. Bhat on 28 April 2014, 18:54:42 UTC, committed by Rafael J. Wysocki on 28 April 2014, 23:22:53 UTC
During frequency transitions, the cpufreq core takes the responsibility of invoking cpufreq_freq_transition_begin() and cpufreq_freq_transition_end() for those cpufreq drivers that define the ->target_index callback but don't set the ASYNC_NOTIFICATION flag. The powernow-k6 cpufreq driver falls under this category, but this driver was invoking the _begin() and _end() APIs itself around frequency transitions, which led to double invocation of the _begin() API. The _begin API makes contending callers wait until the previous invocation is complete. Hence, the powernow-k6 driver ended up waiting on itself, leading to system hangs during boot. Fix this by removing the calls to the _begin() and _end() APIs from the powernow-k6 driver, since they rightly belong to the cpufreq core. (Note that during ->exit(), the powernow-k6 driver sets the frequency without any help from the cpufreq core. So add explicit calls to the _begin() and _end() APIs around that frequency transition alone, to take care of that special case. Also, add a missing 'break' statement there.) Fixes: 12478cf0c55e (cpufreq: Make sure frequency transitions are serialized) Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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