[Intel-gfx] [PATCH] drm/i915: don't force VDD on when shutting down a panel

[Jesse Barnes]

This causes trouble on some VLV systems, and generally costs power
elsewhere.

If this ends up causing trouble, it could just mean we need to get rid
of VDD force enable everywhere, and move to a pure PPS based DP training
sequence.

References: https://bugs.freedesktop.org/show_bug.cgi?id=69693
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_dp.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1e372d5..cb33b67 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1236,9 +1236,7 @@ void ironlake_edp_panel_off(struct intel_dp *intel_dp)
 	WARN(!intel_dp->want_panel_vdd, "Need VDD to turn off panel\n");
 
 	pp = ironlake_get_pp_control(intel_dp);
-	/* We need to switch off panel power _and_ force vdd, for otherwise some
-	 * panels get very unhappy and cease to work. */
-	pp &= ~(POWER_TARGET_ON | EDP_FORCE_VDD | PANEL_POWER_RESET | EDP_BLC_ENABLE);
+	pp &= ~(POWER_TARGET_ON | PANEL_POWER_RESET | EDP_BLC_ENABLE);
 
 	pp_ctrl_reg = _pp_ctrl_reg(intel_dp);
 
-- 
1.8.4.2