1. 22 Mar, 2016 1 commit
  2. 19 Mar, 2016 2 commits
    • Richard Cochran's avatar
      cpufreq: acpi-cpufreq: Clean up hot plug notifier callback · ed72662a
      Richard Cochran authored
      This driver has two issues.  First, it tries to fiddle with the hot
      plugged CPU's MSR on the UP_PREPARE event, at a time when the CPU is
      not yet online.  Second, the driver sets the "boost-disable" bit for a
      CPU when going down, but does not clear the bit again if the CPU comes
      up again due to DOWN_FAILED.
      
      This patch fixes the issues by changing the driver to react to the
      ONLINE/DOWN_FAILED events instead of UP_PREPARE.  As an added benefit,
      the driver also becomes symmetric with respect to the hot plug
      mechanism.
      Signed-off-by: default avatarRichard Cochran <rcochran@linutronix.de>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      ed72662a
    • Rafael J. Wysocki's avatar
      intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts · fdfdb2b1
      Rafael J. Wysocki authored
      After commit a4675fbc (cpufreq: intel_pstate: Replace timers with
      utilization update callbacks) wrmsrl_on_cpu() cannot be called in the
      intel_pstate_adjust_busy_pstate() path as that is executed with
      disabled interrupts.  However, atom_set_pstate() called from there
      via intel_pstate_set_pstate() uses wrmsrl_on_cpu() to update the
      IA32_PERF_CTL MSR which triggers the WARN_ON_ONCE() in
      smp_call_function_single().
      
      The reason why wrmsrl_on_cpu() is used by atom_set_pstate() is
      because intel_pstate_set_pstate() calling it is also invoked during
      the initialization and cleanup of the driver and in those cases it is
      not guaranteed to be run on the CPU that is being updated.  However,
      in the case when intel_pstate_set_pstate() is called by
      intel_pstate_adjust_busy_pstate(), wrmsrl() can be used to update
      the register safely.  Moreover, intel_pstate_set_pstate() already
      contains code that only is executed if the function is called by
      intel_pstate_adjust_busy_pstate() and there is a special argument
      passed to it because of that.
      
      To fix the problem at hand, rearrange the code taking the above
      observations into account.
      
      First, replace the ->set() callback in struct pstate_funcs with a
      ->get_val() one that will return the value to be written to the
      IA32_PERF_CTL MSR without updating the register.
      
      Second, split intel_pstate_set_pstate() into two functions,
      intel_pstate_update_pstate() to be called by
      intel_pstate_adjust_busy_pstate() that will contain all of the
      intel_pstate_set_pstate() code which only needs to be executed in
      that case and will use wrmsrl() to update the MSR (after obtaining
      the value to write to it from the ->get_val() callback), and
      intel_pstate_set_min_pstate() to be invoked during the
      initialization and cleanup that will set the P-state to the
      minimum one and will update the MSR using wrmsrl_on_cpu().
      
      Finally, move the code shared between intel_pstate_update_pstate()
      and intel_pstate_set_min_pstate() to a new static inline function
      intel_pstate_record_pstate() and make them both call it.
      
      Of course, that unifies the handling of the IA32_PERF_CTL MSR writes
      between Atom and Core.
      
      Fixes: a4675fbc (cpufreq: intel_pstate: Replace timers with utilization update callbacks)
      Reported-and-tested-by: default avatarJosh Boyer <jwboyer@fedoraproject.org>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      fdfdb2b1
  3. 18 Mar, 2016 1 commit
  4. 10 Mar, 2016 7 commits
  5. 09 Mar, 2016 29 commits