[Intel-gfx] [PATCH 5/7] drm/i915: don't force matching p1 for g4x/ilk+ reduced pll settings

Daniel Vetter daniel.vetter at ffwll.ch
Fri Apr 19 11:14:35 CEST 2013

g4x dplls and ilk+ pch plls have a separate field for the reduced p1
setting, so this restriction does not apply. Only older platforms have
the restriction that the p1 divisors must match.

This unnecessary restriction has been introduced in

commit cec2f356d59d9e070413e5966a3c5a1af136d948
Author: Sean Paul <seanpaul at chromium.org>
Date:   Tue Jan 10 15:09:36 2012 -0800

    drm/i915: Only look for matching clocks for LVDS downcloc

Note that with lvds the p2 divisors _always_ match for LVDS, and we
don't support auto-downclocking anywhere else. On eDP downclocking
works with separate data m/n settings, using the same link clock.

Cc:  Sean Paul <seanpaul at chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
 drivers/gpu/drm/i915/intel_display.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2a82bd8..9a69d83 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -697,9 +697,6 @@ intel_g4x_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 					if (!intel_PLL_is_valid(dev, limit,
-					if (match_clock &&
-					    clock.p != match_clock->p)
-						continue;
 					this_err = abs(clock.dot - target);
 					if (this_err < err_most) {

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