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Ville Syrjälä authored
On SNB the BIOS provided WM memory latency values seem insufficient to handle high resolution displays. In this particular case the display mode was a 2560x1440@60Hz, which makes the pixel clock 241.5 MHz. It was empirically found that a memory latency value if 1.2 usec is enough to avoid underruns, whereas the BIOS provided value of 0.7 usec was clearly too low. Incidentally 1.2 usec is what the typical BIOS provided values are on IVB systems. Increase the WM memory latency values to at least 1.2 usec on SNB. Hopefully this won't have a significant effect on power consumption. v2: Increase the latency values regardless of the pixel clock Cc: Robert N <crshman@gmail.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70254Tested-by:
Robert Navarro <crshman@gmail.com> Tested-by:
Vitaly Minko <vitaly.minko@gmail.com> Cc: stable@vger.kernel.org Signed-off-by:
Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by:
Jani Nikula <jani.nikula@intel.com>
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