[PATCH 1/3] drm/vmwgfx: Drop svga_lock

[Daniel Vetter]

This isn't actually protecting anything becuase:
- when running, ttm_resource_manager->use_type is protected through
  vmw_private->reservation_semaphore against concurrent execbuf or
  well anything else that might evict or reserve buffers
- during suspend/resume there's nothing else running, hence
  vmw_pm_freeze and vmw_pm_restore do not need to take the same lock.
- this also holds for the SVGA_REG_ENABLE register write

Hence it is safe to just remove that spinlock.

Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Cc: VMware Graphics <linux-graphics-maintainer at vmware.com>
Cc: Roland Scheidegger <sroland at vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 10 +---------
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.h |  1 -
 2 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 0008be02d31c..204f7a1830f0 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -672,7 +672,6 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 	spin_lock_init(&dev_priv->hw_lock);
 	spin_lock_init(&dev_priv->waiter_lock);
 	spin_lock_init(&dev_priv->cap_lock);
-	spin_lock_init(&dev_priv->svga_lock);
 	spin_lock_init(&dev_priv->cursor_lock);
 
 	for (i = vmw_res_context; i < vmw_res_max; ++i) {
@@ -1189,12 +1188,10 @@ static void __vmw_svga_enable(struct vmw_private *dev_priv)
 {
 	struct ttm_resource_manager *man = ttm_manager_type(&dev_priv->bdev, TTM_PL_VRAM);
 
-	spin_lock(&dev_priv->svga_lock);
 	if (!ttm_resource_manager_used(man)) {
 		vmw_write(dev_priv, SVGA_REG_ENABLE, SVGA_REG_ENABLE);
 		ttm_resource_manager_set_used(man, true);
 	}
-	spin_unlock(&dev_priv->svga_lock);
 }
 
 /**
@@ -1220,14 +1217,12 @@ static void __vmw_svga_disable(struct vmw_private *dev_priv)
 {
 	struct ttm_resource_manager *man = ttm_manager_type(&dev_priv->bdev, TTM_PL_VRAM);
 
-	spin_lock(&dev_priv->svga_lock);
 	if (ttm_resource_manager_used(man)) {
 		ttm_resource_manager_set_used(man, false);
 		vmw_write(dev_priv, SVGA_REG_ENABLE,
 			  SVGA_REG_ENABLE_HIDE |
 			  SVGA_REG_ENABLE_ENABLE);
 	}
-	spin_unlock(&dev_priv->svga_lock);
 }
 
 /**
@@ -1254,17 +1249,14 @@ void vmw_svga_disable(struct vmw_private *dev_priv)
 	 */
 	vmw_kms_lost_device(dev_priv->dev);
 	ttm_write_lock(&dev_priv->reservation_sem, false);
-	spin_lock(&dev_priv->svga_lock);
 	if (ttm_resource_manager_used(man)) {
 		ttm_resource_manager_set_used(man, false);
-		spin_unlock(&dev_priv->svga_lock);
 		if (ttm_resource_manager_evict_all(&dev_priv->bdev, man))
 			DRM_ERROR("Failed evicting VRAM buffers.\n");
 		vmw_write(dev_priv, SVGA_REG_ENABLE,
 			  SVGA_REG_ENABLE_HIDE |
 			  SVGA_REG_ENABLE_ENABLE);
-	} else
-		spin_unlock(&dev_priv->svga_lock);
+	}
 	ttm_write_unlock(&dev_priv->reservation_sem);
 }
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 5b9a28157dd3..715f2bfee08a 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -596,7 +596,6 @@ struct vmw_private {
 
 	bool stealth;
 	bool enable_fb;
-	spinlock_t svga_lock;
 
 	/**
 	 * PM management.
-- 
2.29.2