From: Oscar Mateo <oscar.ma...@intel.com>
Or with a spinlock grabbed, because it might sleep, which is not
a nice thing to do. Instead, do the runtime_pm get/put together
with the create/destroy request, and handle the forcewake get/put
directly.
Signed-off-by: Oscar Mateo <oscar.ma...@intel.com>
---
drivers/gpu/drm/i915/intel_lrc.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index d33e622..ea4b358 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -159,6 +159,7 @@ static void execlists_elsp_write(struct intel_engine_cs
*ring,
struct drm_i915_private *dev_priv = ring->dev->dev_private;
uint64_t temp = 0;
uint32_t desc[4];
+ unsigned long flags;
/* XXX: You must always write both descriptors in the order below. */
if (ctx_obj1)
@@ -172,9 +173,17 @@ static void execlists_elsp_write(struct intel_engine_cs
*ring,
desc[3] = (u32)(temp >> 32);
desc[2] = (u32)temp;
- /* Set Force Wakeup bit to prevent GT from entering C6 while
- * ELSP writes are in progress */
- gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
+ /* Set Force Wakeup bit to prevent GT from entering C6 while ELSP writes
+ * are in progress.
+ *
+ * The other problem is that we can't just call gen6_gt_force_wake_get()
+ * because that function calls intel_runtime_pm_get(), which might
sleep.
+ * Instead, we do the runtime_pm_get/put when creating/destroying
requests.
+ */
+ spin_lock_irqsave(&dev_priv->uncore.lock, flags);
+ if (dev_priv->uncore.forcewake_count++ == 0)
+ dev_priv->uncore.funcs.force_wake_get(dev_priv, FORCEWAKE_ALL);
+ spin_unlock_irqrestore(&dev_priv->uncore.lock, flags);
I915_WRITE(RING_ELSP(ring), desc[1]);
I915_WRITE(RING_ELSP(ring), desc[0]);
@@ -185,8 +194,11 @@ static void execlists_elsp_write(struct intel_engine_cs
*ring,
/* ELSP is a write only register, so this serves as a posting read */
POSTING_READ(RING_EXECLIST_STATUS(ring));
- /* Release Force Wakeup */
- gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
+ /* Release Force Wakeup (see the big comment above). */
+ spin_lock_irqsave(&dev_priv->uncore.lock, flags);
+ if (--dev_priv->uncore.forcewake_count == 0)
+ dev_priv->uncore.funcs.force_wake_put(dev_priv, FORCEWAKE_ALL);
+ spin_unlock_irqrestore(&dev_priv->uncore.lock, flags);
}
static int execlists_ctx_write_tail(struct drm_i915_gem_object *ctx_obj, u32
tail)
@@ -353,6 +365,9 @@ static void execlists_free_request_task(struct work_struct
*work)
struct intel_ctx_submit_request *req =
container_of(work, struct intel_ctx_submit_request,
work);
struct drm_device *dev = req->ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ intel_runtime_pm_put(dev_priv);
mutex_lock(&dev->struct_mutex);
i915_gem_context_unreference(req->ctx);
@@ -378,6 +393,7 @@ static int execlists_context_queue(struct intel_engine_cs
*ring,
req->ring = ring;
req->tail = tail;
INIT_WORK(&req->work, execlists_free_request_task);
+ intel_runtime_pm_get(dev_priv);
spin_lock_irqsave(&ring->execlist_lock, flags);
--
1.9.0
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