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>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index bab174334da5..aae346e7f635 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -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_ */