From: Thomas Hellström thomas.hellstrom@intel.com
Any sleeping dma_resv lock taken while the vma pages_mutex is held will cause a lockdep splat. Move the i915_gem_object_pin_pages() call out of the pages_mutex critical section.
Signed-off-by: Thomas Hellström thomas.hellstrom@intel.com --- drivers/gpu/drm/i915/i915_vma.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index a6cd0fa62847..7b1c0f4e60d7 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -800,32 +800,37 @@ static bool try_qad_pin(struct i915_vma *vma, unsigned int flags) static int vma_get_pages(struct i915_vma *vma) { int err = 0; + bool pinned_pages = false;
if (atomic_add_unless(&vma->pages_count, 1, 0)) return 0;
+ if (vma->obj) { + err = i915_gem_object_pin_pages(vma->obj); + if (err) + return err; + pinned_pages = true; + } + /* Allocations ahoy! */ - if (mutex_lock_interruptible(&vma->pages_mutex)) - return -EINTR; + if (mutex_lock_interruptible(&vma->pages_mutex)) { + err = -EINTR; + goto unpin; + }
if (!atomic_read(&vma->pages_count)) { - if (vma->obj) { - err = i915_gem_object_pin_pages(vma->obj); - if (err) - goto unlock; - } - err = vma->ops->set_pages(vma); - if (err) { - if (vma->obj) - i915_gem_object_unpin_pages(vma->obj); + if (err) goto unlock; - } + pinned_pages = false; } atomic_inc(&vma->pages_count);
unlock: mutex_unlock(&vma->pages_mutex); +unpin: + if (pinned_pages) + __i915_gem_object_unpin_pages(vma->obj);
return err; } @@ -838,10 +843,10 @@ static void __vma_put_pages(struct i915_vma *vma, unsigned int count) if (atomic_sub_return(count, &vma->pages_count) == 0) { vma->ops->clear_pages(vma); GEM_BUG_ON(vma->pages); - if (vma->obj) - i915_gem_object_unpin_pages(vma->obj); } mutex_unlock(&vma->pages_mutex); + if (vma->obj) + i915_gem_object_unpin_pages(vma->obj); }
static void vma_put_pages(struct i915_vma *vma)