drm/i915: Track pfit enable state separately from size

Detangle the additional state of whether or not the hw has the pfit
enabled from whether it has zero size. This allows us to cleanly
distinguish in the code when we expect the pfit to be enabled (for
Haswell pc8), and when the BIOS is confused and needs sanitizing.

Reported-by: shui yanwei <[e-mail]>
Signed-off-by: Chris Wilson <[e-mail]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68251
Tested-by: shui yanwei <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>

drivers/gpu/drm/i915/intel_ddi.c

···
 			/* Can only use the always-on power well for eDP when
 			 * not using the panel fitter, and when not using motion
 			  * blur mitigation (which we don't support). */
-			if (intel_crtc->config.pch_pfit.size)
+			if (intel_crtc->config.pch_pfit.enabled)
 				temp |= TRANS_DDI_EDP_INPUT_A_ONOFF;
 			else
 				temp |= TRANS_DDI_EDP_INPUT_A_ON;

drivers/gpu/drm/i915/intel_display.c

···
 		I915_WRITE(PIPESRC(intel_crtc->pipe),
 			   ((crtc->mode.hdisplay - 1) << 16) |
 			   (crtc->mode.vdisplay - 1));
-		if (!intel_crtc->config.pch_pfit.size &&
+		if (!intel_crtc->config.pch_pfit.enabled &&
 		    (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS) ||
 		     intel_pipe_has_type(crtc, INTEL_OUTPUT_EDP))) {
 			I915_WRITE(PF_CTL(intel_crtc->pipe), 0);
···
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int pipe = crtc->pipe;
 
-	if (crtc->config.pch_pfit.size) {
+	if (crtc->config.pch_pfit.enabled) {
 		/* Force use of hard-coded filter coefficients
 		 * as some pre-programmed values are broken,
 		 * e.g. x201.
···
 
 	/* To avoid upsetting the power well on haswell only disable the pfit if
 	 * it's in use. The hw state code will make sure we get this right. */
-	if (crtc->config.pch_pfit.size) {
+	if (crtc->config.pch_pfit.enabled) {
 		I915_WRITE(PF_CTL(pipe), 0);
 		I915_WRITE(PF_WIN_POS(pipe), 0);
 		I915_WRITE(PF_WIN_SZ(pipe), 0);
···
 	tmp = I915_READ(PF_CTL(crtc->pipe));
 
 	if (tmp & PF_ENABLE) {
+		pipe_config->pch_pfit.enabled = true;
 		pipe_config->pch_pfit.pos = I915_READ(PF_WIN_POS(crtc->pipe));
 		pipe_config->pch_pfit.size = I915_READ(PF_WIN_SZ(crtc->pipe));
 
···
 		if (!crtc->base.enabled)
 			continue;
 
-		if (crtc->pipe != PIPE_A || crtc->config.pch_pfit.size ||
+		if (crtc->pipe != PIPE_A || crtc->config.pch_pfit.enabled ||
 		    crtc->config.cpu_transcoder != TRANSCODER_EDP)
 			enable = true;
 	}
···
 		      pipe_config->gmch_pfit.control,
 		      pipe_config->gmch_pfit.pgm_ratios,
 		      pipe_config->gmch_pfit.lvds_border_bits);
-	DRM_DEBUG_KMS("pch pfit: pos: 0x%08x, size: 0x%08x\n",
+	DRM_DEBUG_KMS("pch pfit: pos: 0x%08x, size: 0x%08x, %s\n",
 		      pipe_config->pch_pfit.pos,
-		      pipe_config->pch_pfit.size);
+		      pipe_config->pch_pfit.size,
+		      pipe_config->pch_pfit.enabled ? "enabled" : "disabled");
 	DRM_DEBUG_KMS("ips: %i\n", pipe_config->ips_enabled);
 }
 
···
 	if (INTEL_INFO(dev)->gen < 4)
 		PIPE_CONF_CHECK_I(gmch_pfit.pgm_ratios);
 	PIPE_CONF_CHECK_I(gmch_pfit.lvds_border_bits);
-	PIPE_CONF_CHECK_I(pch_pfit.pos);
-	PIPE_CONF_CHECK_I(pch_pfit.size);
+	PIPE_CONF_CHECK_I(pch_pfit.enabled);
+	if (current_config->pch_pfit.enabled) {
+		PIPE_CONF_CHECK_I(pch_pfit.pos);
+		PIPE_CONF_CHECK_I(pch_pfit.size);
+	}
 
 	PIPE_CONF_CHECK_I(ips_enabled);
 

drivers/gpu/drm/i915/intel_drv.h

···
 	struct {
 		u32 pos;
 		u32 size;
+		bool enabled;
 	} pch_pfit;
 
 	/* FDI configuration, only valid if has_pch_encoder is set. */

drivers/gpu/drm/i915/intel_panel.c

···
 done:
 	pipe_config->pch_pfit.pos = (x << 16) | y;
 	pipe_config->pch_pfit.size = (width << 16) | height;
+	pipe_config->pch_pfit.enabled = pipe_config->pch_pfit.size != 0;
 }
 
 static void

drivers/gpu/drm/i915/intel_pm.c

···
 				    struct drm_crtc *crtc)
 {
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
-	uint32_t pixel_rate, pfit_size;
+	uint32_t pixel_rate;
 
 	pixel_rate = intel_crtc->config.adjusted_mode.clock;
 
 	/* We only use IF-ID interlacing. If we ever use PF-ID we'll need to
 	 * adjust the pixel_rate here. */
 
-	pfit_size = intel_crtc->config.pch_pfit.size;
-	if (pfit_size) {
+	if (intel_crtc->config.pch_pfit.enabled) {
 		uint64_t pipe_w, pipe_h, pfit_w, pfit_h;
+		uint32_t pfit_size = intel_crtc->config.pch_pfit.size;
 
 		pipe_w = intel_crtc->config.requested_mode.hdisplay;
 		pipe_h = intel_crtc->config.requested_mode.vdisplay;