On Tue, 7 Oct 2014 14:13:51 +0100 Chris Wilson chris@chris-wilson.co.uk wrote:

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

---

drivers/gpu/drm/drm_fops.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index ed7bc68f7e87..91e1105f2800 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -515,10 +515,12 @@ ssize_t drm_read(struct file *filp, char __user *buffer, 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 @@ ssize_t drm_read(struct file *filp, char __user *buffer, e->destroy(e); }

• return total;

• return total ?: -EAGAIN;

} EXPORT_SYMBOL(drm_read);

I'd prefer "total" to be spelled out after the ? (is this just a GNU thing or does recent C implicitly use the first operand too?), but that's no biggie. Looks fine.

Reviewed-by: Jesse Barnes jbarnes@virtuousgeek.org