drm/i915: save/restore interrupt state

On resume, if the interrupt state isn't restored correctly, we may end
up with a flood of unexpected or ill-timed interrupts, which could cause
the kernel to disable the interrupt or vblank events to happen at the
wrong time.  So save/restore them properly.

Signed-off-by: Dave Airlie <airlied@linux.ie>

drivers/char/drm/i915_drv.c

@@ -276,6 +276,7 @@ static int i915_suspend(struct drm_device *dev)
 		dev_priv->saveDSPATILEOFF = I915_READ(DSPATILEOFF);
 	}
 	i915_save_palette(dev, PIPE_A);
+	dev_priv->savePIPEASTAT = I915_READ(I915REG_PIPEASTAT);
 
 	/* Pipe & plane B info */
 	dev_priv->savePIPEBCONF = I915_READ(PIPEBCONF);
@@ -303,6 +304,7 @@ static int i915_suspend(struct drm_device *dev)
 		dev_priv->saveDSPBTILEOFF = I915_READ(DSPBTILEOFF);
 	}
 	i915_save_palette(dev, PIPE_B);
+	dev_priv->savePIPEBSTAT = I915_READ(I915REG_PIPEBSTAT);
 
 	/* CRT state */
 	dev_priv->saveADPA = I915_READ(ADPA);
@@ -329,6 +331,11 @@ static int i915_suspend(struct drm_device *dev)
 	dev_priv->saveFBC_CONTROL2 = I915_READ(FBC_CONTROL2);
 	dev_priv->saveFBC_CONTROL = I915_READ(FBC_CONTROL);
 
+	/* Interrupt state */
+	dev_priv->saveIIR = I915_READ(I915REG_INT_IDENTITY_R);
+	dev_priv->saveIER = I915_READ(I915REG_INT_ENABLE_R);
+	dev_priv->saveIMR = I915_READ(I915REG_INT_MASK_R);
+
 	/* VGA state */
 	dev_priv->saveVCLK_DIVISOR_VGA0 = I915_READ(VCLK_DIVISOR_VGA0);
 	dev_priv->saveVCLK_DIVISOR_VGA1 = I915_READ(VCLK_DIVISOR_VGA1);

drivers/char/drm/i915_drv.h

@@ -134,6 +134,7 @@ typedef struct drm_i915_private {
 	u32 saveVBLANK_A;
 	u32 saveVSYNC_A;
 	u32 saveBCLRPAT_A;
+	u32 savePIPEASTAT;
 	u32 saveDSPASTRIDE;
 	u32 saveDSPASIZE;
 	u32 saveDSPAPOS;
@@ -154,6 +155,7 @@ typedef struct drm_i915_private {
 	u32 saveVBLANK_B;
 	u32 saveVSYNC_B;
 	u32 saveBCLRPAT_B;
+	u32 savePIPEBSTAT;
 	u32 saveDSPBSTRIDE;
 	u32 saveDSPBSIZE;
 	u32 saveDSPBPOS;
@@ -182,6 +184,9 @@ typedef struct drm_i915_private {
 	u32 saveFBC_LL_BASE;
 	u32 saveFBC_CONTROL;
 	u32 saveFBC_CONTROL2;
+	u32 saveIER;
+	u32 saveIIR;
+	u32 saveIMR;
 	u32 saveSWF0[16];
 	u32 saveSWF1[16];
 	u32 saveSWF2[3];