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Vidya Srinivas authored
PFI credit programming is required when CD clock (related to data flow from display pipeline to end display) is greater than CZ clock (related to data flow from memory to display plane). This programming should be done when all planes are OFF to avoid intermittent hangs while accessing memory even from different Gfx units (not just display). If cdclk/czclk >=1, PFI credits could be set as any number. To get better performance, larger PFI credit can be assigned to PND. Otherwise if cdclk/czclk<1, the default PFI credit of 8 should be set. v2: - Change log to lower log level instead of DRM_ERROR - Change function name to valleyview_program_pfi_credits - Move program PFI credits to modeset_init instead of intel_set_mode - Change magic numbers to logical constants [vsyrjala v3: - only program in response to cdclk update - program the credits also when cdclk<czclk - add CHV bits v4: - Change CHV cdclk<czclk credits to 12 (Vijay)] Signed-off-by:
Vidya Srinivas <vidya.srinivas@intel.com> Signed-off-by:
Gajanan Bhat <gajanan.bhat@intel.com> Signed-off-by:
Vandana Kannan <vandana.kannan@intel.com> Signed-off-by:
Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by:
Vijay Purushothaman <vijay.a.purushothaman@linux.intel.com> Signed-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch>
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