drm: Implement O_NONBLOCK support on /dev/dri/cardN
The implmentation is simple in the extreme: we only want to wait for
events if the device was opened in blocking mode, otherwise we grab what
is available and report an error if there was none.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Testcase: igt/kms_flip/nonblocing_read
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index ed7bc68..91e1105 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -515,10 +515,12 @@
size_t total;
ssize_t ret;
- ret = wait_event_interruptible(file_priv->event_wait,
- !list_empty(&file_priv->event_list));
- if (ret < 0)
- return ret;
+ if ((filp->f_flags & O_NONBLOCK) == 0) {
+ ret = wait_event_interruptible(file_priv->event_wait,
+ !list_empty(&file_priv->event_list));
+ if (ret < 0)
+ return ret;
+ }
total = 0;
while (drm_dequeue_event(file_priv, total, count, &e)) {
@@ -532,7 +534,7 @@
e->destroy(e);
}
- return total;
+ return total ?: -EAGAIN;
}
EXPORT_SYMBOL(drm_read);