For eDP in the Intel driver pps_lock()/unlock() need to be called before initiating an I2C/AUX channel transfer. These operations can be quite expensive - especially on values for HZ lower than 1000. It is therefore better to perfrom this locking/unlocking only once, ie at the beginning and at the end of the entire I2C transfer. The current design of drm_dp_helper.c doesn't allow this. This patchset modifies drm_dp_helper.c and moves the locking/unlocking operation to the top. This fixes the long delay observed in https://bugs.freedesktop.org/show_bug.cgi?id=86201 Egbert Eich (4): drm/DP: Create pointer to generic DPCD access function drm/DP: Export drm_dp_i2c_xfer() DP helper function drm/DP: Export drm_dp_dpcd_access() DP helper function drm/i915/eDP: Move pps_lock() and edp_panel_vdd_on() to top Ville Syrjälä (1): drm/i915: Try to avoid pps_{lock,unlock}() on DP ports drivers/gpu/drm/drm_dp_helper.c | 11 ++-- drivers/gpu/drm/i915/intel_dp.c | 132 +++++++++++++++++++++++++++++++-------- drivers/gpu/drm/i915/intel_drv.h | 5 ++ include/drm/drm_dp_helper.h | 14 +++++ 4 files changed, 133 insertions(+), 29 deletions(-) -- 1.8.4.5 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
