patches.baytrail/0369-drm-i915-reinit-status-page-registers-after-gpu-rese.patch

From 02b4f8bd472ddf7a976ebe56ce11324b6e940304 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Wed, 3 Jul 2013 12:56:54 +0200
Subject: drm/i915: reinit status page registers after gpu reset

This fixes gpu reset on my gm45 - without this patch the bsd thing is
forever stuck since the seqno updates never reach the status page.

Tbh I have no idea how this ever worked without rewriting the hws
registers after a gpu reset.

To satisfy my OCD also give the functions a bit more consistent names:
- Use status_page everywhere, also for the physical addressed one.
- Use init for the allocation part and setup for the register setup
  part consistently.

Long term I'd really like to share the hw init parts completely
between gpu reset, resume and driver load, i.e. to call
i915_gem_init_hw instead of the individual pieces we might need.

v2: Add the missing paragraph to the commit message about what bug
exactly this patch here fixes.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65495
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: lu hua <huax.lu@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 035dc1e0f9008b48630e02bf0eaa7cc547416d1d)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_ringbuffer.c |   29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -382,6 +382,17 @@ u32 intel_ring_get_active_head(struct in
 	return I915_READ(acthd_reg);
 }
 
+static void ring_setup_phys_status_page(struct intel_ring_buffer *ring)
+{
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
+	u32 addr;
+
+	addr = dev_priv->status_page_dmah->busaddr;
+	if (INTEL_INFO(ring->dev)->gen >= 4)
+		addr |= (dev_priv->status_page_dmah->busaddr >> 28) & 0xf0;
+	I915_WRITE(HWS_PGA, addr);
+}
+
 static int init_ring_common(struct intel_ring_buffer *ring)
 {
 	struct drm_device *dev = ring->dev;
@@ -393,6 +404,11 @@ static int init_ring_common(struct intel
 	if (HAS_FORCE_WAKE(dev))
 		gen6_gt_force_wake_get(dev_priv);
 
+	if (I915_NEED_GFX_HWS(dev))
+		intel_ring_setup_status_page(ring);
+	else
+		ring_setup_phys_status_page(ring);
+
 	/* Stop the ring if it's running. */
 	I915_WRITE_CTL(ring, 0);
 	I915_WRITE_HEAD(ring, 0);
@@ -1240,7 +1256,6 @@ static int init_status_page(struct intel
 	ring->status_page.obj = obj;
 	memset(ring->status_page.page_addr, 0, PAGE_SIZE);
 
-	intel_ring_setup_status_page(ring);
 	DRM_DEBUG_DRIVER("%s hws offset: 0x%08x\n",
 			ring->name, ring->status_page.gfx_addr);
 
@@ -1254,10 +1269,9 @@ err:
 	return ret;
 }
 
-static int init_phys_hws_pga(struct intel_ring_buffer *ring)
+static int init_phys_status_page(struct intel_ring_buffer *ring)
 {
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
-	u32 addr;
 
 	if (!dev_priv->status_page_dmah) {
 		dev_priv->status_page_dmah =
@@ -1266,11 +1280,6 @@ static int init_phys_hws_pga(struct inte
 			return -ENOMEM;
 	}
 
-	addr = dev_priv->status_page_dmah->busaddr;
-	if (INTEL_INFO(ring->dev)->gen >= 4)
-		addr |= (dev_priv->status_page_dmah->busaddr >> 28) & 0xf0;
-	I915_WRITE(HWS_PGA, addr);
-
 	ring->status_page.page_addr = dev_priv->status_page_dmah->vaddr;
 	memset(ring->status_page.page_addr, 0, PAGE_SIZE);
 
@@ -1298,7 +1307,7 @@ static int intel_init_ring_buffer(struct
 			return ret;
 	} else {
 		BUG_ON(ring->id != RCS);
-		ret = init_phys_hws_pga(ring);
+		ret = init_phys_status_page(ring);
 		if (ret)
 			return ret;
 	}
@@ -1914,7 +1923,7 @@ int intel_render_ring_init_dri(struct dr
 	}
 
 	if (!I915_NEED_GFX_HWS(dev)) {
-		ret = init_phys_hws_pga(ring);
+		ret = init_phys_status_page(ring);
 		if (ret)
 			return ret;
 	}