From 86dfb76cba284114cf586005cd943eeb6e4f328d Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi Date: Wed, 7 Sep 2016 17:42:31 -0700 Subject: [PATCH] Revert "drm/i915/psr: Make idle_frames sensible again" This reverts commit 1c80c25fb622973dd135878e98d172be20859049 Author: Daniel Vetter Date: Wed May 18 18:47:12 2016 +0200 drm/i915/psr: Make idle_frames sensible again There are panels that needs 4 idle frames before entering PSR, but VBT is unproperly set. Also lately it was identified that idle frame count calculated at HW can be off by 1, what makes the minimum of 2, at least. Without the current vbt+1 we are with the risk of having HW calculating 0 idle frames and entering PSR when it shouldn't. Regardless the lack of link training. [Jani: there is some disagreement on the explanation, but the commit regresses so revert it is.] References: http://marc.info/?i=20160904191153.GA2328@light.dominikbrodowski.net Cc: Dominik Brodowski Cc: Jani Nikula Cc: Daniel Vetter Signed-off-by: Rodrigo Vivi Fixes: 1c80c25fb622 ("drm/i915/psr: Make idle_frames sensible again") Cc: drm-intel-fixes@lists.freedesktop.org # v4.8-rc1+ Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/1473295351-8766-1-git-send-email-rodrigo.vivi@intel.com (cherry picked from commit 40918e0bb81be02f507a941f8b2741f0dc1771b0) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_psr.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c index 2b0d1ba..cf171b4 100644 --- a/drivers/gpu/drm/i915/intel_psr.c +++ b/drivers/gpu/drm/i915/intel_psr.c @@ -255,14 +255,14 @@ static void hsw_psr_enable_source(struct intel_dp *intel_dp) struct drm_i915_private *dev_priv = to_i915(dev); uint32_t max_sleep_time = 0x1f; - /* Lately it was identified that depending on panel idle frame count - * calculated at HW can be off by 1. So let's use what came - * from VBT + 1. - * There are also other cases where panel demands at least 4 - * but VBT is not being set. To cover these 2 cases lets use - * at least 5 when VBT isn't set to be on the safest side. + /* + * Let's respect VBT in case VBT asks a higher idle_frame value. + * Let's use 6 as the minimum to cover all known cases including + * the off-by-one issue that HW has in some cases. Also there are + * cases where sink should be able to train + * with the 5 or 6 idle patterns. */ - uint32_t idle_frames = dev_priv->vbt.psr.idle_frames + 1; + uint32_t idle_frames = max(6, dev_priv->vbt.psr.idle_frames); uint32_t val = EDP_PSR_ENABLE; val |= max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT; -- 2.7.4