drm/i915: Inifite timeout for wait ioctl

Change the ns_timeout parameter of the wait ioctl to a signed value.
Doing this allows the kernel to provide an infinite wait when a timeout
of less than 0 is provided. This mimics select/poll.

Initially the parameter was meant to match up with the GL spec 1:1, but
after being made aware of how much 2^64 - 1 nanoseconds actually is, I
do not think anyone will ever notice the loss of 1 bit.

The infinite timeout on waiting is similar to the existing i915
userspace interface with the exception that struct_mutex is dropped
while doing the wait in this ioctl.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ben Widawsky 2012-06-05 15:24:24 -07:00 committed by Daniel Vetter
parent de9a35abb3
commit eac1f14fd1
2 changed files with 11 additions and 6 deletions

View File

@ -2082,11 +2082,14 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
struct drm_i915_gem_wait *args = data;
struct drm_i915_gem_object *obj;
struct intel_ring_buffer *ring = NULL;
struct timespec timeout;
struct timespec timeout_stack, *timeout = NULL;
u32 seqno = 0;
int ret = 0;
timeout = ns_to_timespec(args->timeout_ns);
if (args->timeout_ns >= 0) {
timeout_stack = ns_to_timespec(args->timeout_ns);
timeout = &timeout_stack;
}
ret = i915_mutex_lock_interruptible(dev);
if (ret)
@ -2122,9 +2125,11 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
drm_gem_object_unreference(&obj->base);
mutex_unlock(&dev->struct_mutex);
ret = __wait_seqno(ring, seqno, true, &timeout);
WARN_ON(!timespec_valid(&timeout));
args->timeout_ns = timespec_to_ns(&timeout);
ret = __wait_seqno(ring, seqno, true, timeout);
if (timeout) {
WARN_ON(!timespec_valid(timeout));
args->timeout_ns = timespec_to_ns(timeout);
}
return ret;
out:

View File

@ -893,7 +893,7 @@ struct drm_i915_gem_wait {
__u32 bo_handle;
__u32 flags;
/** Number of nanoseconds to wait, Returns time remaining. */
__u64 timeout_ns;
__s64 timeout_ns;
};
#endif /* _I915_DRM_H_ */