[Intel-gfx] [PATCH 0/5] drm/i915 Avoid long delays when reading EDID on eDP

[Jani Nikula]

On Mon, 24 Nov 2014, Egbert Eich <eich at suse.de> wrote:
> 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

These three need to be sent to dri-devel, with cc: Thierry Reding
<thierry.reding at gmail.com>.

BR,
Jani.

>   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
>
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-- 
Jani Nikula, Intel Open Source Technology Center