From 9c75b185274b7766fe69c2e73607c1ed780b284b Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Wed, 28 Jun 2017 18:06:05 -0300 Subject: [PATCH] drm/i915: reintroduce VLV/CHV PFI programming power domain workaround MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit There are still cases on these platforms where an attempt is made to configure the CDCLK while the power domain is off, like when coming back from a suspend. So the workaround below is still needed. This effectively reverts commit 63ff30442519 ("drm/i915: Nuke the VLV/CHV PFI programming power domain workaround"). Cc: stable@vger.kernel.org Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101517 Suggested-by: Ville Syrjälä Signed-off-by: Gabriel Krisman Bertazi Link: http://patchwork.freedesktop.org/patch/msgid/20170628210605.4994-1-krisman@collabora.co.uk Reviewed-by: Ville Syrjälä Signed-off-by: Ville Syrjälä (cherry picked from commit 886015a0ad43c7fc034b23ea4614ba39162f9ddd) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_cdclk.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index b8914db7d2e1..1241e5891b29 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -491,6 +491,14 @@ static void vlv_set_cdclk(struct drm_i915_private *dev_priv, int cdclk = cdclk_state->cdclk; u32 val, cmd; + /* There are cases where we can end up here with power domains + * off and a CDCLK frequency other than the minimum, like when + * issuing a modeset without actually changing any display after + * a system suspend. So grab the PIPE-A domain, which covers + * the HW blocks needed for the following programming. + */ + intel_display_power_get(dev_priv, POWER_DOMAIN_PIPE_A); + if (cdclk >= 320000) /* jump to highest voltage for 400MHz too */ cmd = 2; else if (cdclk == 266667) @@ -549,6 +557,8 @@ static void vlv_set_cdclk(struct drm_i915_private *dev_priv, intel_update_cdclk(dev_priv); vlv_program_pfi_credits(dev_priv); + + intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE_A); } static void chv_set_cdclk(struct drm_i915_private *dev_priv, @@ -568,6 +578,14 @@ static void chv_set_cdclk(struct drm_i915_private *dev_priv, return; } + /* There are cases where we can end up here with power domains + * off and a CDCLK frequency other than the minimum, like when + * issuing a modeset without actually changing any display after + * a system suspend. So grab the PIPE-A domain, which covers + * the HW blocks needed for the following programming. + */ + intel_display_power_get(dev_priv, POWER_DOMAIN_PIPE_A); + /* * Specs are full of misinformation, but testing on actual * hardware has shown that we just need to write the desired @@ -590,6 +608,8 @@ static void chv_set_cdclk(struct drm_i915_private *dev_priv, intel_update_cdclk(dev_priv); vlv_program_pfi_credits(dev_priv); + + intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE_A); } static int bdw_calc_cdclk(int max_pixclk) -- 2.30.2