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 at chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
drivers/gpu/drm/i915/i915_gem.c | 15 ++++++++++-----
include/drm/i915_drm.h | 2 +-
2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3bc918c..b2eacde 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2026,11 +2026,14 @@ 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)
@@ -2073,9 +2076,11 @@ 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:
diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index bab1743..aae346e 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_ */
--
1.7.10.3
