drm/i915: Save/restore HWS_PGA on suspend/resume

It fixes suspend/resume failure of xf86-video-intel dri2
branch. As dri2 branch doesn't call I830DRIResume() to restore
hardware status page anymore, we need to preserve
this register across suspend/resume.

Signed-off-by: Peng Li <peng.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b24d522f490c..0a4f39b9a0ec 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -150,6 +150,7 @@ typedef struct drm_i915_private {
         u32 saveDSPBCNTR;
         u32 saveDSPARB;
         u32 saveRENDERSTANDBY;
+        u32 saveHWS;
         u32 savePIPEACONF;
         u32 savePIPEBCONF;
         u32 savePIPEASRC;
diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 5ddc6e595c0c..5d84027ee8f3 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -244,6 +244,9 @@ int i915_save_state(struct drm_device *dev)
         if (IS_I965G(dev) && IS_MOBILE(dev))
                 dev_priv->saveRENDERSTANDBY = I915_READ(MCHBAR_RENDER_STANDBY);
 
+        /* Hardware status page */
+        dev_priv->saveHWS = I915_READ(HWS_PGA);
+
         /* Display arbitration control */
         dev_priv->saveDSPARB = I915_READ(DSPARB);
 
@@ -373,6 +376,9 @@ int i915_restore_state(struct drm_device *dev)
         if (IS_I965G(dev) && IS_MOBILE(dev))
                 I915_WRITE(MCHBAR_RENDER_STANDBY, dev_priv->saveRENDERSTANDBY);
 
+        /* Hardware status page */
+        I915_WRITE(HWS_PGA, dev_priv->saveHWS);
+
         /* Display arbitration */
         I915_WRITE(DSPARB, dev_priv->saveDSPARB);