From 5caa0feafcc60a2457d8187c2fa06a3df67c8ba2 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue, 9 May 2017 16:03:29 +0200
Subject: [PATCH] drm/vblank: Lock down vblank->hwmode more
Mime-version: 1.0
Content-type: text/plain; charset=UTF-8
Content-transfer-encoding: 8bit
Git-commit: 5caa0feafcc60a2457d8187c2fa06a3df67c8ba2
Patch-mainline: v4.13-rc1
References: FATE#322643 bsc#1055900

In the previous patch we've implemented hwmode tracking a la i915 for
the vblank timestamp calculations. But that was just the basic
semantics, i915 has some nice sanity checks to make sure we keep
getting this right. Move them over too.

V2: 
- WARN_ON_ONCE to avoid excessive spam (Ville)
- Really only WARN on atomic drivers.

Cc: Ville Syrj채l채 <ville.syrjala@linux.intel.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Ville Syrj채l채 <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-5-daniel.vetter@ffwll.ch
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/drm_irq.c            |    6 ++++++
 drivers/gpu/drm/i915/i915_irq.c      |   10 ++++++----
 drivers/gpu/drm/i915/intel_display.c |   11 ++---------
 3 files changed, 14 insertions(+), 13 deletions(-)

--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -777,6 +777,8 @@ bool drm_calc_vbltimestamp_from_scanoutp
 	 */
 	if (mode->crtc_clock == 0) {
 		DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
+		WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev));
+
 		return false;
 	}
 
@@ -1338,6 +1340,10 @@ void drm_crtc_vblank_off(struct drm_crtc
 		send_vblank_event(dev, e, seq, &now);
 	}
 	spin_unlock_irqrestore(&dev->event_lock, irqflags);
+
+	/* Will be reset by the modeset helpers when re-enabling the crtc by
+	 * calling drm_calc_timestamping_constants(). */
+	vblank->hwmode.crtc_clock = 0;
 }
 EXPORT_SYMBOL(drm_crtc_vblank_off);
 
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -720,9 +720,7 @@ static u32 i915_get_vblank_counter(struc
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	i915_reg_t high_frame, low_frame;
 	u32 high1, high2, low, pixel, vbl_start, hsync_start, htotal;
-	struct intel_crtc *intel_crtc = intel_get_crtc_for_pipe(dev_priv,
-								pipe);
-	const struct drm_display_mode *mode = &intel_crtc->base.hwmode;
+	const struct drm_display_mode *mode = &dev->vblank[pipe].hwmode;
 	unsigned long irqflags;
 
 	htotal = mode->crtc_htotal;
@@ -779,13 +777,17 @@ static int __intel_get_crtc_scanline(str
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
-	const struct drm_display_mode *mode = &crtc->base.hwmode;
+	const struct drm_display_mode *mode;
+	struct drm_vblank_crtc *vblank;
 	enum pipe pipe = crtc->pipe;
 	int position, vtotal;
 
 	if (!crtc->active)
 		return -1;
 
+	vblank = &crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];
+	mode = &vblank->hwmode;
+
 	vtotal = mode->crtc_vtotal;
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		vtotal /= 2;
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11454,12 +11454,6 @@ intel_modeset_update_crtc_state(struct d
 	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
 		to_intel_crtc(crtc)->config = to_intel_crtc_state(new_crtc_state);
 
-		/* Update hwmode for vblank functions */
-		if (new_crtc_state->active)
-			crtc->hwmode = new_crtc_state->adjusted_mode;
-		else
-			crtc->hwmode.crtc_clock = 0;
-
 		/*
 		 * Update legacy state to satisfy fbc code. This can
 		 * be removed when fbc uses the atomic state.
@@ -15445,8 +15439,6 @@ static void intel_modeset_readout_hw_sta
 			to_intel_crtc_state(crtc->base.state);
 		int pixclk = 0;
 
-		crtc->base.hwmode = crtc_state->base.adjusted_mode;
-
 		memset(&crtc->base.mode, 0, sizeof(crtc->base.mode));
 		if (crtc_state->base.active) {
 			intel_mode_from_pipe_config(&crtc->base.mode, crtc_state);
@@ -15476,7 +15468,8 @@ static void intel_modeset_readout_hw_sta
 			if (IS_BROADWELL(dev_priv) && crtc_state->ips_enabled)
 				pixclk = DIV_ROUND_UP(pixclk * 100, 95);
 
-			drm_calc_timestamping_constants(&crtc->base, &crtc->base.hwmode);
+			drm_calc_timestamping_constants(&crtc->base,
+							&crtc_state->base.adjusted_mode);
 			update_scanline_offset(crtc);
 		}