[PATCH v1 2/2] drm/panfrost: Fix wait_bo ioctl leaking positive return from dma_resv_wait_timeout()

[Gyeyoung Baek <gye976@gmail.com>]

dma_resv_wait_timeout() returns a positive 'remaining jiffies' value
on success, 0 on timeout, and -errno on failure.

panfrost_ioctl_wait_bo() returns this 'long' result from an int-typed
ioctl handler, so positive values reach userspace as bogus errors.
Explicitly set ret to 0 on the success path.

Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
Cc: stable@vger.kernel.org
Signed-off-by: Gyeyoung Baek <gye976@gmail.com>
---
 drivers/gpu/drm/panfrost/panfrost_drv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 3d0bdba2a..784e36d72 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -390,6 +390,8 @@ panfrost_ioctl_wait_bo(struct drm_device *dev, void *data,
 				    true, timeout);
 	if (!ret)
 		ret = timeout ? -ETIMEDOUT : -EBUSY;
+	else if (ret > 0)
+		ret = 0;
 
 	drm_gem_object_put(gem_obj);
 
-- 
2.43.0