drm/i915: Disallow preallocation of requests
The intention was to allow the caller to avoid a failure to queue a
request having already written commands to the ring. However, this is a
moot point as the i915_add_request() can fail for other reasons than a
mere allocation failure and those failure cases are more likely than
ENOMEM. So the overlay code already had to handle i915_add_request()
failures, and due to
commit 3bb73aba1ed5198a2c1dfaac4f3c95459930d84a
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri Jul 20 12:40:59 2012 +0100
drm/i915: Allow late allocation of request for i915_add_request()
the error handling code in intel_overlay.c was subject to causing
double-frees, as found by coverity.
Rather than further complicate i915_add_request() and callers, realise
the battle is lost and adapt intel_overlay.c to take advantage of the
late allocation of requests.
v2: Handle callers passing in a NULL seqno.
v3: Ditto. This time for sure.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 53de95c..04b0c07 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1956,11 +1956,12 @@
int
i915_add_request(struct intel_ring_buffer *ring,
struct drm_file *file,
- struct drm_i915_gem_request *request)
+ u32 *out_seqno)
{
drm_i915_private_t *dev_priv = ring->dev->dev_private;
- uint32_t seqno;
+ struct drm_i915_gem_request *request;
u32 request_ring_position;
+ u32 seqno;
int was_empty;
int ret;
@@ -1975,11 +1976,9 @@
if (ret)
return ret;
- if (request == NULL) {
- request = kmalloc(sizeof(*request), GFP_KERNEL);
- if (request == NULL)
- return -ENOMEM;
- }
+ request = kmalloc(sizeof(*request), GFP_KERNEL);
+ if (request == NULL)
+ return -ENOMEM;
seqno = i915_gem_next_request_seqno(ring);
@@ -2031,6 +2030,8 @@
}
}
+ if (out_seqno)
+ *out_seqno = seqno;
return 0;
}