drm/vmwgfx: Fix a circular locking dependency bug.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
index 4157547..39d43a0 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
@@ -74,6 +74,7 @@
fifo->reserved_size = 0;
fifo->using_bounce_buffer = false;
+ mutex_init(&fifo->fifo_mutex);
init_rwsem(&fifo->rwsem);
/*
@@ -117,7 +118,7 @@
(unsigned int) min,
(unsigned int) fifo->capabilities);
- dev_priv->fence_seq = dev_priv->last_read_sequence;
+ atomic_set(&dev_priv->fence_seq, dev_priv->last_read_sequence);
iowrite32(dev_priv->last_read_sequence, fifo_mem + SVGA_FIFO_FENCE);
return vmw_fifo_send_fence(dev_priv, &dummy);
@@ -283,7 +284,7 @@
uint32_t reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
int ret;
- down_write(&fifo_state->rwsem);
+ mutex_lock(&fifo_state->fifo_mutex);
max = ioread32(fifo_mem + SVGA_FIFO_MAX);
min = ioread32(fifo_mem + SVGA_FIFO_MIN);
next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
@@ -351,7 +352,7 @@
}
out_err:
fifo_state->reserved_size = 0;
- up_write(&fifo_state->rwsem);
+ mutex_unlock(&fifo_state->fifo_mutex);
return NULL;
}
@@ -426,6 +427,7 @@
}
+ down_write(&fifo_state->rwsem);
if (fifo_state->using_bounce_buffer || reserveable) {
next_cmd += bytes;
if (next_cmd >= max)
@@ -437,8 +439,9 @@
if (reserveable)
iowrite32(0, fifo_mem + SVGA_FIFO_RESERVED);
mb();
- vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
up_write(&fifo_state->rwsem);
+ vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
+ mutex_unlock(&fifo_state->fifo_mutex);
}
int vmw_fifo_send_fence(struct vmw_private *dev_priv, uint32_t *sequence)
@@ -451,9 +454,7 @@
fm = vmw_fifo_reserve(dev_priv, bytes);
if (unlikely(fm == NULL)) {
- down_write(&fifo_state->rwsem);
- *sequence = dev_priv->fence_seq;
- up_write(&fifo_state->rwsem);
+ *sequence = atomic_read(&dev_priv->fence_seq);
ret = -ENOMEM;
(void)vmw_fallback_wait(dev_priv, false, true, *sequence,
false, 3*HZ);
@@ -461,7 +462,7 @@
}
do {
- *sequence = dev_priv->fence_seq++;
+ *sequence = atomic_add_return(1, &dev_priv->fence_seq);
} while (*sequence == 0);
if (!(fifo_state->capabilities & SVGA_FIFO_CAP_FENCE)) {