[Intel-gfx] [PATCH] drm/i915: Do not put big intel_crtc_state on the stack

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Having this on stack triggers the -Wframe-larger-than=1024 and
is not nice to put such big things on the kernel stack anyway.

This required a little bit of refactoring to handle the new
failure path from vlv_force_pll_on.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: John Harrison <john.c.harrison at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
Compile tested only!
---
 drivers/gpu/drm/i915/intel_display.c | 58 +++++++++++++++++++++++-------------
 drivers/gpu/drm/i915/intel_dp.c      |  8 +++--
 drivers/gpu/drm/i915/intel_drv.h     |  4 +--
 3 files changed, 45 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ccb3e3f47450..7bf18658c659 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7635,26 +7635,34 @@ static void chv_prepare_pll(struct intel_crtc *crtc,
  * in cases where we need the PLL enabled even when @pipe is not going to
  * be enabled.
  */
-void vlv_force_pll_on(struct drm_device *dev, enum pipe pipe,
+int vlv_force_pll_on(struct drm_device *dev, enum pipe pipe,
 		      const struct dpll *dpll)
 {
 	struct intel_crtc *crtc =
 		to_intel_crtc(intel_get_crtc_for_pipe(dev, pipe));
-	struct intel_crtc_state pipe_config = {
-		.base.crtc = &crtc->base,
-		.pixel_multiplier = 1,
-		.dpll = *dpll,
-	};
+	struct intel_crtc_state *pipe_config;
+
+	pipe_config = kzalloc(sizeof(*pipe_config), GFP_KERNEL);
+	if (!pipe_config)
+		return -ENOMEM;
+
+	pipe_config->base.crtc = &crtc->base;
+	pipe_config->pixel_multiplier = 1;
+	pipe_config->dpll = *dpll;
 
 	if (IS_CHERRYVIEW(dev)) {
-		chv_compute_dpll(crtc, &pipe_config);
-		chv_prepare_pll(crtc, &pipe_config);
-		chv_enable_pll(crtc, &pipe_config);
+		chv_compute_dpll(crtc, pipe_config);
+		chv_prepare_pll(crtc, pipe_config);
+		chv_enable_pll(crtc, pipe_config);
 	} else {
-		vlv_compute_dpll(crtc, &pipe_config);
-		vlv_prepare_pll(crtc, &pipe_config);
-		vlv_enable_pll(crtc, &pipe_config);
+		vlv_compute_dpll(crtc, pipe_config);
+		vlv_prepare_pll(crtc, pipe_config);
+		vlv_enable_pll(crtc, pipe_config);
 	}
+
+	kfree(pipe_config);
+
+	return 0;
 }
 
 /**
@@ -10828,7 +10836,7 @@ struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	enum transcoder cpu_transcoder = intel_crtc->config->cpu_transcoder;
 	struct drm_display_mode *mode;
-	struct intel_crtc_state pipe_config;
+	struct intel_crtc_state *pipe_config;
 	int htot = I915_READ(HTOTAL(cpu_transcoder));
 	int hsync = I915_READ(HSYNC(cpu_transcoder));
 	int vtot = I915_READ(VTOTAL(cpu_transcoder));
@@ -10839,6 +10847,12 @@ struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
 	if (!mode)
 		return NULL;
 
+	pipe_config = kzalloc(sizeof(*pipe_config), GFP_KERNEL);
+	if (!pipe_config) {
+		kfree(mode);
+		return NULL;
+	}
+
 	/*
 	 * Construct a pipe_config sufficient for getting the clock info
 	 * back out of crtc_clock_get.
@@ -10846,14 +10860,14 @@ struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
 	 * Note, if LVDS ever uses a non-1 pixel multiplier, we'll need
 	 * to use a real value here instead.
 	 */
-	pipe_config.cpu_transcoder = (enum transcoder) pipe;
-	pipe_config.pixel_multiplier = 1;
-	pipe_config.dpll_hw_state.dpll = I915_READ(DPLL(pipe));
-	pipe_config.dpll_hw_state.fp0 = I915_READ(FP0(pipe));
-	pipe_config.dpll_hw_state.fp1 = I915_READ(FP1(pipe));
-	i9xx_crtc_clock_get(intel_crtc, &pipe_config);
-
-	mode->clock = pipe_config.port_clock / pipe_config.pixel_multiplier;
+	pipe_config->cpu_transcoder = (enum transcoder) pipe;
+	pipe_config->pixel_multiplier = 1;
+	pipe_config->dpll_hw_state.dpll = I915_READ(DPLL(pipe));
+	pipe_config->dpll_hw_state.fp0 = I915_READ(FP0(pipe));
+	pipe_config->dpll_hw_state.fp1 = I915_READ(FP1(pipe));
+	i9xx_crtc_clock_get(intel_crtc, pipe_config);
+
+	mode->clock = pipe_config->port_clock / pipe_config->pixel_multiplier;
 	mode->hdisplay = (htot & 0xffff) + 1;
 	mode->htotal = ((htot & 0xffff0000) >> 16) + 1;
 	mode->hsync_start = (hsync & 0xffff) + 1;
@@ -10865,6 +10879,8 @@ struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
 
 	drm_mode_set_name(mode);
 
+	kfree(pipe_config);
+
 	return mode;
 }
 
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 17612548c58d..e2bea710614f 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -335,8 +335,12 @@ vlv_power_sequencer_kick(struct intel_dp *intel_dp)
 		release_cl_override = IS_CHERRYVIEW(dev) &&
 			!chv_phy_powergate_ch(dev_priv, phy, ch, true);
 
-		vlv_force_pll_on(dev, pipe, IS_CHERRYVIEW(dev) ?
-				 &chv_dpll[0].dpll : &vlv_dpll[0].dpll);
+		if (vlv_force_pll_on(dev, pipe, IS_CHERRYVIEW(dev) ?
+				     &chv_dpll[0].dpll : &vlv_dpll[0].dpll)) {
+			DRM_ERROR("Failed to force on pll for pipe %c!\n",
+				  pipe_name(pipe));
+			return;
+		}
 	}
 
 	/*
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 059b46e22c31..538faaf4eeef 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1177,8 +1177,8 @@ void assert_shared_dpll(struct drm_i915_private *dev_priv,
 struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc,
 						struct intel_crtc_state *state);
 
-void vlv_force_pll_on(struct drm_device *dev, enum pipe pipe,
-		      const struct dpll *dpll);
+int vlv_force_pll_on(struct drm_device *dev, enum pipe pipe,
+		     const struct dpll *dpll);
 void vlv_force_pll_off(struct drm_device *dev, enum pipe pipe);
 
 /* modesetting asserts */
-- 
1.9.1