drm/i915: don't enable self-refresh on Ironlake

We don't know how to enable it safely, especially as outputs turn on and
off. When disabling LP1 we also need to make sure LP2 and 3 are already
disabled.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29173
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29082
Reported-by: Chris Lord <[e-mail]>
Signed-off-by: Jesse Barnes <[e-mail]>
Tested-by: Daniel Vetter <[e-mail]>
Cc: [e-mail]
Signed-off-by: Chris Wilson <[e-mail]>

drivers/gpu/drm/i915/i915_reg.h

···
 #define  WM1_LP_SR_EN		(1<<31)
 #define  WM1_LP_LATENCY_SHIFT	24
 #define  WM1_LP_LATENCY_MASK	(0x7f<<24)
+#define  WM1_LP_FBC_LP1_MASK	(0xf<<20)
+#define  WM1_LP_FBC_LP1_SHIFT	20
 #define  WM1_LP_SR_MASK		(0x1ff<<8)
 #define  WM1_LP_SR_SHIFT	8
 #define  WM1_LP_CURSOR_MASK	(0x3f)
+#define WM2_LP_ILK		0x4510c
+#define  WM2_LP_EN		(1<<31)
+#define WM3_LP_ILK		0x45110
+#define  WM3_LP_EN		(1<<31)
+#define WM1S_LP_ILK		0x45120
+#define  WM1S_LP_EN		(1<<31)
 
 /* Memory latency timer register */
 #define MLTR_ILK		0x11222

drivers/gpu/drm/i915/intel_display.c

···
 		reg_value = I915_READ(WM1_LP_ILK);
 		reg_value &= ~(WM1_LP_LATENCY_MASK | WM1_LP_SR_MASK |
 			       WM1_LP_CURSOR_MASK);
-		reg_value |= WM1_LP_SR_EN |
-			     (ilk_sr_latency << WM1_LP_LATENCY_SHIFT) |
+		reg_value |= (ilk_sr_latency << WM1_LP_LATENCY_SHIFT) |
 			     (sr_wm << WM1_LP_SR_SHIFT) | cursor_wm;
 
 		I915_WRITE(WM1_LP_ILK, reg_value);
···
 			I915_WRITE(DISP_ARB_CTL,
 					(I915_READ(DISP_ARB_CTL) |
 						DISP_FBC_WM_DIS));
+		I915_WRITE(WM3_LP_ILK, 0);
+		I915_WRITE(WM2_LP_ILK, 0);
+		I915_WRITE(WM1_LP_ILK, 0);
 		}
 		/*
 		 * Based on the document from hardware guys the following bits