1. 19 May, 2016 37 commits
  2. 11 May, 2016 3 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.5.4 · a29ab351
      Greg Kroah-Hartman authored
      a29ab351
    • Srinivas Pandruvada's avatar
      ACPI / processor: Request native thermal interrupt handling via _OSC · 0d5406b6
      Srinivas Pandruvada authored
      commit a2121167 upstream.
      
      There are several reports of freeze on enabling HWP (Hardware PStates)
      feature on Skylake-based systems by the Intel P-states driver. The root
      cause is identified as the HWP interrupts causing BIOS code to freeze.
      
      HWP interrupts use the thermal LVT which can be handled by Linux
      natively, but on the affected Skylake-based systems SMM will respond
      to it by default.  This is a problem for several reasons:
       - On the affected systems the SMM thermal LVT handler is broken (it
         will crash when invoked) and a BIOS update is necessary to fix it.
       - With thermal interrupt handled in SMM we lose all of the reporting
         features of the arch/x86/kernel/cpu/mcheck/therm_throt driver.
       - Some thermal drivers like x86-package-temp depend on the thermal
         threshold interrupts signaled via the thermal LVT.
       - The HWP interrupts are useful for debugging and tuning
         performance (if the kernel can handle them).
      The native handling of thermal interrupts needs to be enabled
      because of that.
      
      This requires some way to tell SMM that the OS can handle thermal
      interrupts.  That can be done by using _OSC/_PDC in processor
      scope very early during ACPI initialization.
      
      The meaning of _OSC/_PDC bit 12 in processor scope is whether or
      not the OS supports native handling of interrupts for Collaborative
      Processor Performance Control (CPPC) notifications.  Since on
      HWP-capable systems CPPC is a firmware interface to HWP, setting
      this bit effectively tells the firmware that the OS will handle
      thermal interrupts natively going forward.
      
      For details on _OSC/_PDC refer to:
      http://www.intel.com/content/www/us/en/standards/processor-vendor-specific-acpi-specification.html
      
      To implement the _OSC/_PDC handshake as described, introduce a new
      function, acpi_early_processor_osc(), that walks the ACPI
      namespace looking for ACPI processor objects and invokes _OSC for
      them with bit 12 in the capabilities buffer set and terminates the
      namespace walk on the first success.
      
      Also modify intel_thermal_interrupt() to clear HWP status bits in
      the HWP_STATUS MSR to acknowledge HWP interrupts (which prevents
      them from firing continuously).
      Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
      [ rjw: Subject & changelog, function rename ]
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0d5406b6
    • Shashank Sharma's avatar
      drm/i915: Fake HDMI live status · 833a9558
      Shashank Sharma authored
      commit 60b3143c upstream.
      
      This patch does the following:
      - Fakes live status of HDMI as connected (even if that's not).
        While testing certain (monitor + cable) combinations with
        various intel  platforms, it seems that live status register
        doesn't work reliably on some older devices. So limit the
        live_status check for HDMI detection, only for platforms
        from gen7 onwards.
      
      V2: restrict faking live_status to certain platforms
      V3: (Ville)
         - keep the debug message for !live_status case
         - fix indentation of comment
         - remove "warning" from the debug message
      
          (Jani)
         - Change format of fix details in the commit message
      
      Fixes: 237ed86c ("drm/i915: Check live status before reading edid")
      Suggested-by: default avatarVille Syrjala <ville.syrjala@linux.intel.com>
      Signed-off-by: default avatarShashank Sharma <shashank.sharma@intel.com>
      Link: http://patchwork.freedesktop.org/patch/msgid/1461237606-16491-1-git-send-email-shashank.sharma@intel.comSigned-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
      (cherry picked from commit 4f4a8185)
      Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      833a9558