The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 53421c2fe99ce16838639ad89d772d914a119a49 Mon Sep 17 00:00:00 2001
From: Lucas De Marchi lucas.demarchi@intel.com Date: Mon, 4 Dec 2017 15:22:10 -0800 Subject: [PATCH] drm/i915: Apply Display WA #1183 on skl, kbl, and cfl MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
Display WA #1183 was recently added to workaround "Failures when enabling DPLL0 with eDP link rate 2.16 or 4.32 GHz and CD clock frequency 308.57 or 617.14 MHz (CDCLK_CTL CD Frequency Select 10b or 11b) used in this enabling or in previous enabling."
This workaround was designed to minimize the impact only to save the bad case with that link rates. But HW engineers indicated that it should be safe to apply broadly, although they were expecting the DPLL0 link rate to be unchanged on runtime.
We need to cover 2 cases: when we are in fact enabling DPLL0 and when we are just changing the frequency with small differences.
This is based on previous patch by Rodrigo Vivi with suggestions from Ville Syrjälä.
Cc: Arthur J Runyan arthur.j.runyan@intel.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Rodrigo Vivi rodrigo.vivi@intel.com Cc: stable@vger.kernel.org Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20171204232210.4958-1-lucas.de...
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 41285bec8fc0..966e4df9700e 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -7029,6 +7029,7 @@ enum { #define RESET_PCH_HANDSHAKE_ENABLE (1<<4)
#define GEN8_CHICKEN_DCPR_1 _MMIO(0x46430) +#define SKL_SELECT_ALTERNATE_DC_EXIT (1<<30) #define MASK_WAKEMEM (1<<13)
#define SKL_DFSM _MMIO(0x51000) @@ -8585,6 +8586,7 @@ enum skl_power_gate { #define BXT_CDCLK_CD2X_DIV_SEL_2 (2<<22) #define BXT_CDCLK_CD2X_DIV_SEL_4 (3<<22) #define BXT_CDCLK_CD2X_PIPE(pipe) ((pipe)<<20) +#define CDCLK_DIVMUX_CD_OVERRIDE (1<<19) #define BXT_CDCLK_CD2X_PIPE_NONE BXT_CDCLK_CD2X_PIPE(3) #define BXT_CDCLK_SSA_PRECHARGE_ENABLE (1<<16) #define CDCLK_FREQ_DECIMAL_MASK (0x7ff) diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index 9c5ceb98d48f..d77e2bec1e29 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -931,16 +931,10 @@ static void skl_set_preferred_cdclk_vco(struct drm_i915_private *dev_priv,
static void skl_dpll0_enable(struct drm_i915_private *dev_priv, int vco) { - int min_cdclk = skl_calc_cdclk(0, vco); u32 val;
WARN_ON(vco != 8100000 && vco != 8640000);
- /* select the minimum CDCLK before enabling DPLL 0 */ - val = CDCLK_FREQ_337_308 | skl_cdclk_decimal(min_cdclk); - I915_WRITE(CDCLK_CTL, val); - POSTING_READ(CDCLK_CTL); - /* * We always enable DPLL0 with the lowest link rate possible, but still * taking into account the VCO required to operate the eDP panel at the @@ -994,7 +988,7 @@ static void skl_set_cdclk(struct drm_i915_private *dev_priv, { int cdclk = cdclk_state->cdclk; int vco = cdclk_state->vco; - u32 freq_select; + u32 freq_select, cdclk_ctl; int ret;
mutex_lock(&dev_priv->pcu_lock); @@ -1009,7 +1003,7 @@ static void skl_set_cdclk(struct drm_i915_private *dev_priv, return; }
- /* set CDCLK_CTL */ + /* Choose frequency for this cdclk */ switch (cdclk) { default: WARN_ON(cdclk != dev_priv->cdclk.hw.ref); @@ -1036,10 +1030,33 @@ static void skl_set_cdclk(struct drm_i915_private *dev_priv, dev_priv->cdclk.hw.vco != vco) skl_dpll0_disable(dev_priv);
+ cdclk_ctl = I915_READ(CDCLK_CTL); + + if (dev_priv->cdclk.hw.vco != vco) { + /* Wa Display #1183: skl,kbl,cfl */ + cdclk_ctl &= ~(CDCLK_FREQ_SEL_MASK | CDCLK_FREQ_DECIMAL_MASK); + cdclk_ctl |= freq_select | skl_cdclk_decimal(cdclk); + I915_WRITE(CDCLK_CTL, cdclk_ctl); + } + + /* Wa Display #1183: skl,kbl,cfl */ + cdclk_ctl |= CDCLK_DIVMUX_CD_OVERRIDE; + I915_WRITE(CDCLK_CTL, cdclk_ctl); + POSTING_READ(CDCLK_CTL); + if (dev_priv->cdclk.hw.vco != vco) skl_dpll0_enable(dev_priv, vco);
- I915_WRITE(CDCLK_CTL, freq_select | skl_cdclk_decimal(cdclk)); + /* Wa Display #1183: skl,kbl,cfl */ + cdclk_ctl &= ~(CDCLK_FREQ_SEL_MASK | CDCLK_FREQ_DECIMAL_MASK); + I915_WRITE(CDCLK_CTL, cdclk_ctl); + + cdclk_ctl |= freq_select | skl_cdclk_decimal(cdclk); + I915_WRITE(CDCLK_CTL, cdclk_ctl); + + /* Wa Display #1183: skl,kbl,cfl */ + cdclk_ctl &= ~CDCLK_DIVMUX_CD_OVERRIDE; + I915_WRITE(CDCLK_CTL, cdclk_ctl); POSTING_READ(CDCLK_CTL);
/* inform PCU of the change */ diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index db9d57f39534..d758da6156a8 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -600,6 +600,11 @@ void gen9_enable_dc5(struct drm_i915_private *dev_priv)
DRM_DEBUG_KMS("Enabling DC5\n");
+ /* Wa Display #1183: skl,kbl,cfl */ + if (IS_GEN9_BC(dev_priv)) + I915_WRITE(GEN8_CHICKEN_DCPR_1, I915_READ(GEN8_CHICKEN_DCPR_1) | + SKL_SELECT_ALTERNATE_DC_EXIT); + gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC5); }
@@ -627,6 +632,11 @@ void skl_disable_dc6(struct drm_i915_private *dev_priv) { DRM_DEBUG_KMS("Disabling DC6\n");
+ /* Wa Display #1183: skl,kbl,cfl */ + if (IS_GEN9_BC(dev_priv)) + I915_WRITE(GEN8_CHICKEN_DCPR_1, I915_READ(GEN8_CHICKEN_DCPR_1) | + SKL_SELECT_ALTERNATE_DC_EXIT); + gen9_set_dc_state(dev_priv, DC_STATE_DISABLE); }