[PATCH 2/4] drm/i915: Fix context/engine cleanup order

Dave Gordon
2016-01-21T19:37:54Z

From: Nick Hoath <nicholas.hoath@intel.com>

Swap the order of context & engine cleanup, so that contexts are cleaned
up first, and *then* engines. This is a more sensible order anyway, but
in particular has become necessary since the 'intel_ring_initialized()
must be simple and inline' patch, which now uses ring->dev as an
'initialised' flag, so it can now be NULL after engine teardown. This
in turn can cause a problem in the context code, which (used to) check
the ring->dev->struct_mutex -- causing a fault if ring->dev was NULL.

Also rename the cleanup function to reflect what it actually does
(cleanup engines, not a ringbuffer), and fix an annoying whitespace issue.

v2: Also make the fix in i915_load_modeset_init, not just in
i915_driver_unload (Chris Wilson)
v3: Had extra stuff in it.
v4: Reverted extra stuff (so we're back to v2).
Rebased and updated commentary above (Dave Gordon).

Signed-off-by: Nick Hoath <nicholas.hoath@intel.com>
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>

---
drivers/gpu/drm/i915/i915_dma.c | 4 ++--
drivers/gpu/drm/i915/i915_drv.h | 2 +-
drivers/gpu/drm/i915/i915_gem.c | 23 ++++++++++++-----------
3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index d70d96f..4725e8d 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -451,8 +451,8 @@ static int i915_load_modeset_init(struct drm_device *dev)

cleanup_gem:
mutex_lock(&dev->struct_mutex);
- i915_gem_cleanup_ringbuffer(dev);
i915_gem_context_fini(dev);
+ i915_gem_cleanup_engines(dev);
mutex_unlock(&dev->struct_mutex);
cleanup_irq:
intel_guc_ucode_fini(dev);
@@ -1196,8 +1196,8 @@ int i915_driver_unload(struct drm_device *dev)

intel_guc_ucode_fini(dev);
mutex_lock(&dev->struct_mutex);
- i915_gem_cleanup_ringbuffer(dev);
i915_gem_context_fini(dev);
+ i915_gem_cleanup_engines(dev);
mutex_unlock(&dev->struct_mutex);
intel_fbc_cleanup_cfb(dev_priv);
i915_gem_cleanup_stolen(dev);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 204661f..021e88a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3012,7 +3012,7 @@ int i915_gem_init_rings(struct drm_device *dev);
int __must_check i915_gem_init_hw(struct drm_device *dev);
int i915_gem_l3_remap(struct drm_i915_gem_request *req, int slice);
void i915_gem_init_swizzling(struct drm_device *dev);
-void i915_gem_cleanup_ringbuffer(struct drm_device *dev);
+void i915_gem_cleanup_engines(struct drm_device *dev);
int __must_check i915_gpu_idle(struct drm_device *dev);
int __must_check i915_gem_suspend(struct drm_device *dev);
void __i915_add_request(struct drm_i915_gem_request *req,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 371bbb2..799a53a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4912,7 +4912,7 @@ int i915_gem_init_rings(struct drm_device *dev)
req = i915_gem_request_alloc(ring, NULL);
if (IS_ERR(req)) {
ret = PTR_ERR(req);
- i915_gem_cleanup_ringbuffer(dev);
+ i915_gem_cleanup_engines(dev);
goto out;
}

@@ -4925,7 +4925,7 @@ int i915_gem_init_rings(struct drm_device *dev)
if (ret && ret != -EIO) {
DRM_ERROR("PPGTT enable ring #%d failed %d\n", i, ret);
i915_gem_request_cancel(req);
- i915_gem_cleanup_ringbuffer(dev);
+ i915_gem_cleanup_engines(dev);
goto out;
}

@@ -4933,7 +4933,7 @@ int i915_gem_init_rings(struct drm_device *dev)
if (ret && ret != -EIO) {
DRM_ERROR("Context enable ring #%d failed %d\n", i, ret);
i915_gem_request_cancel(req);
- i915_gem_cleanup_ringbuffer(dev);
+ i915_gem_cleanup_engines(dev);
goto out;
}

@@ -5008,7 +5008,7 @@ int i915_gem_init(struct drm_device *dev)
}

void
-i915_gem_cleanup_ringbuffer(struct drm_device *dev)
+i915_gem_cleanup_engines(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_engine_cs *ring;
@@ -5017,13 +5017,14 @@ int i915_gem_init(struct drm_device *dev)
for_each_ring(ring, dev_priv, i)
dev_priv->gt.cleanup_ring(ring);

- if (i915.enable_execlists)
- /*
- * Neither the BIOS, ourselves or any other kernel
- * expects the system to be in execlists mode on startup,
- * so we need to reset the GPU back to legacy mode.
- */
- intel_gpu_reset(dev);
+ if (i915.enable_execlists) {
+ /*
+ * Neither the BIOS, ourselves or any other kernel
+ * expects the system to be in execlists mode on startup,
+ * so we need to reset the GPU back to legacy mode.
+ */
+ intel_gpu_reset(dev);
+ }
}

static void
--
1.9.1