drm/i915: change no_fbc_reason from enum to string

I wanted to add yet another check to intel_fbc_update() and realized
I would need to create yet another enum no_fbc_reason case. So I
remembered this patch series that Damien wrote a long time ago and
nobody ever reviewed, so I decided to reimplement it since the code
changed a lot since then.

Credits-to: Damien Lespiau <damien.lespiau@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445964628-30226-2-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -1644,7 +1644,7 @@ static int i915_fbc_status(struct seq_file *m, void *unused)
 		seq_puts(m, "FBC enabled\n");
 	else
 		seq_printf(m, "FBC disabled: %s\n",
-			  intel_no_fbc_reason_str(dev_priv->fbc.no_fbc_reason));
+			   dev_priv->fbc.no_fbc_reason);
 
 	if (INTEL_INFO(dev_priv)->gen >= 7)
 		seq_printf(m, "Compressing: %s\n",

drivers/gpu/drm/i915/i915_drv.h

@@ -925,24 +925,7 @@ struct i915_fbc {
 		struct drm_framebuffer *fb;
 	} *fbc_work;
 
-	enum no_fbc_reason {
-		FBC_OK, /* FBC is enabled */
-		FBC_UNSUPPORTED, /* FBC is not supported by this chipset */
-		FBC_NO_OUTPUT, /* no outputs enabled to compress */
-		FBC_STOLEN_TOO_SMALL, /* not enough space for buffers */
-		FBC_UNSUPPORTED_MODE, /* interlace or doublescanned mode */
-		FBC_MODE_TOO_LARGE, /* mode too large for compression */
-		FBC_BAD_PLANE, /* fbc not supported on plane */
-		FBC_NOT_TILED, /* buffer not tiled */
-		FBC_MULTIPLE_PIPES, /* more than one pipe active */
-		FBC_MODULE_PARAM,
-		FBC_CHIP_DEFAULT, /* disabled by default on this chip */
-		FBC_ROTATION, /* rotation is not supported */
-		FBC_IN_DBG_MASTER, /* kernel debugger is active */
-		FBC_BAD_STRIDE, /* stride is not supported */
-		FBC_PIXEL_RATE, /* pixel rate is too big */
-		FBC_PIXEL_FORMAT /* pixel format is invalid */
-	} no_fbc_reason;
+	const char *no_fbc_reason;
 
 	bool (*fbc_enabled)(struct drm_i915_private *dev_priv);
 	void (*enable_fbc)(struct intel_crtc *crtc);

drivers/gpu/drm/i915/intel_drv.h

@@ -1304,7 +1304,6 @@ void intel_fbc_invalidate(struct drm_i915_private *dev_priv,
 			  enum fb_op_origin origin);
 void intel_fbc_flush(struct drm_i915_private *dev_priv,
 		     unsigned int frontbuffer_bits, enum fb_op_origin origin);
-const char *intel_no_fbc_reason_str(enum no_fbc_reason reason);
 void intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv);
 
 /* intel_hdmi.c */

drivers/gpu/drm/i915/intel_fbc.c

@@ -471,55 +471,14 @@ void intel_fbc_disable_crtc(struct intel_crtc *crtc)
 	mutex_unlock(&dev_priv->fbc.lock);
 }
 
-const char *intel_no_fbc_reason_str(enum no_fbc_reason reason)
-{
-	switch (reason) {
-	case FBC_OK:
-		return "FBC enabled but currently disabled in hardware";
-	case FBC_UNSUPPORTED:
-		return "unsupported by this chipset";
-	case FBC_NO_OUTPUT:
-		return "no output";
-	case FBC_STOLEN_TOO_SMALL:
-		return "not enough stolen memory";
-	case FBC_UNSUPPORTED_MODE:
-		return "mode incompatible with compression";
-	case FBC_MODE_TOO_LARGE:
-		return "mode too large for compression";
-	case FBC_BAD_PLANE:
-		return "FBC unsupported on plane";
-	case FBC_NOT_TILED:
-		return "framebuffer not tiled or fenced";
-	case FBC_MULTIPLE_PIPES:
-		return "more than one pipe active";
-	case FBC_MODULE_PARAM:
-		return "disabled per module param";
-	case FBC_CHIP_DEFAULT:
-		return "disabled per chip default";
-	case FBC_ROTATION:
-		return "rotation unsupported";
-	case FBC_IN_DBG_MASTER:
-		return "Kernel debugger is active";
-	case FBC_BAD_STRIDE:
-		return "framebuffer stride not supported";
-	case FBC_PIXEL_RATE:
-		return "pixel rate is too big";
-	case FBC_PIXEL_FORMAT:
-		return "pixel format is invalid";
-	default:
-		MISSING_CASE(reason);
-		return "unknown reason";
-	}
-}
-
 static void set_no_fbc_reason(struct drm_i915_private *dev_priv,
-			      enum no_fbc_reason reason)
+			      const char *reason)
 {
 	if (dev_priv->fbc.no_fbc_reason == reason)
 		return;
 
 	dev_priv->fbc.no_fbc_reason = reason;
-	DRM_DEBUG_KMS("Disabling FBC: %s\n", intel_no_fbc_reason_str(reason));
+	DRM_DEBUG_KMS("Disabling FBC: %s\n", reason);
 }
 
 static struct drm_crtc *intel_fbc_find_crtc(struct drm_i915_private *dev_priv)
@@ -863,12 +822,12 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 		i915.enable_fbc = 0;
 
 	if (i915.enable_fbc < 0) {
-		set_no_fbc_reason(dev_priv, FBC_CHIP_DEFAULT);
+		set_no_fbc_reason(dev_priv, "disabled per chip default");
 		goto out_disable;
 	}
 
 	if (!i915.enable_fbc) {
-		set_no_fbc_reason(dev_priv, FBC_MODULE_PARAM);
+		set_no_fbc_reason(dev_priv, "disabled per module param");
 		goto out_disable;
 	}
 
@@ -883,12 +842,12 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 	 */
 	crtc = intel_fbc_find_crtc(dev_priv);
 	if (!crtc) {
-		set_no_fbc_reason(dev_priv, FBC_NO_OUTPUT);
+		set_no_fbc_reason(dev_priv, "no output");
 		goto out_disable;
 	}
 
 	if (!multiple_pipes_ok(dev_priv)) {
-		set_no_fbc_reason(dev_priv, FBC_MULTIPLE_PIPES);
+		set_no_fbc_reason(dev_priv, "more than one pipe active");
 		goto out_disable;
 	}
 
@@ -899,18 +858,18 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 
 	if ((adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) ||
 	    (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)) {
-		set_no_fbc_reason(dev_priv, FBC_UNSUPPORTED_MODE);
+		set_no_fbc_reason(dev_priv, "incompatible mode");
 		goto out_disable;
 	}
 
 	if (!intel_fbc_hw_tracking_covers_screen(intel_crtc)) {
-		set_no_fbc_reason(dev_priv, FBC_MODE_TOO_LARGE);
+		set_no_fbc_reason(dev_priv, "mode too large for compression");
 		goto out_disable;
 	}
 
 	if ((INTEL_INFO(dev_priv)->gen < 4 || HAS_DDI(dev_priv)) &&
 	    intel_crtc->plane != PLANE_A) {
-		set_no_fbc_reason(dev_priv, FBC_BAD_PLANE);
+		set_no_fbc_reason(dev_priv, "FBC unsupported on plane");
 		goto out_disable;
 	}
 
@@ -919,28 +878,28 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 	 */
 	if (obj->tiling_mode != I915_TILING_X ||
 	    obj->fence_reg == I915_FENCE_REG_NONE) {
-		set_no_fbc_reason(dev_priv, FBC_NOT_TILED);
+		set_no_fbc_reason(dev_priv, "framebuffer not tiled or fenced");
 		goto out_disable;
 	}
 	if (INTEL_INFO(dev_priv)->gen <= 4 && !IS_G4X(dev_priv) &&
 	    crtc->primary->state->rotation != BIT(DRM_ROTATE_0)) {
-		set_no_fbc_reason(dev_priv, FBC_ROTATION);
+		set_no_fbc_reason(dev_priv, "rotation unsupported");
 		goto out_disable;
 	}
 
 	if (!stride_is_valid(dev_priv, fb->pitches[0])) {
-		set_no_fbc_reason(dev_priv, FBC_BAD_STRIDE);
+		set_no_fbc_reason(dev_priv, "framebuffer stride not supported");
 		goto out_disable;
 	}
 
 	if (!pixel_format_is_valid(fb)) {
-		set_no_fbc_reason(dev_priv, FBC_PIXEL_FORMAT);
+		set_no_fbc_reason(dev_priv, "pixel format is invalid");
 		goto out_disable;
 	}
 
 	/* If the kernel debugger is active, always disable compression */
 	if (in_dbg_master()) {
-		set_no_fbc_reason(dev_priv, FBC_IN_DBG_MASTER);
+		set_no_fbc_reason(dev_priv, "Kernel debugger is active");
 		goto out_disable;
 	}
 
@@ -948,12 +907,12 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 	if ((IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) &&
 	    ilk_pipe_pixel_rate(intel_crtc->config) >=
 	    dev_priv->cdclk_freq * 95 / 100) {
-		set_no_fbc_reason(dev_priv, FBC_PIXEL_RATE);
+		set_no_fbc_reason(dev_priv, "pixel rate is too big");
 		goto out_disable;
 	}
 
 	if (intel_fbc_setup_cfb(intel_crtc)) {
-		set_no_fbc_reason(dev_priv, FBC_STOLEN_TOO_SMALL);
+		set_no_fbc_reason(dev_priv, "not enough stolen memory");
 		goto out_disable;
 	}
 
@@ -996,7 +955,7 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
 	}
 
 	intel_fbc_schedule_enable(intel_crtc);
-	dev_priv->fbc.no_fbc_reason = FBC_OK;
+	dev_priv->fbc.no_fbc_reason = "FBC enabled (not necessarily active)\n";
 	return;
 
 out_disable:
@@ -1089,7 +1048,7 @@ void intel_fbc_init(struct drm_i915_private *dev_priv)
 
 	if (!HAS_FBC(dev_priv)) {
 		dev_priv->fbc.enabled = false;
-		dev_priv->fbc.no_fbc_reason = FBC_UNSUPPORTED;
+		dev_priv->fbc.no_fbc_reason = "unsupported by this chipset";
 		return;
 	}