Re: [PATCH 3/6] drm/atomic: Don't overrun the connector array when hotplugging

On Wed, Nov 19, 2014 at 06:38:08PM +0100, Daniel Vetter wrote: [...]

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c

[...]

@@ -304,6 +306,21 @@ drm_atomic_get_connector_state(struct drm_atomic_state *state,

index = drm_connector_index(connector);

• /*

• * Construction of atomic state updates can race with a connector
  

• * hot-add which might overflow. In this case flip the table and just
  

• * restart the entire ioctl - no one is fast enough to livelock a cpu
  

• * with physical hotplug events anyway.
  

• *
  

• * Note that we only grab the indexes once we have the right lock to
  

• * prevent hotplug/unplugging of connectors. So removal is no problem,
  

• * at most the array is a bit too large.
  

• */
  

• if (index >= state->num_connector) {

• DRM_DEBUG_KMS("Hot-added connector would overflow state array, restarting\n");
  

• return -EAGAIN;
  

This function returns a pointer, so this needs to be ERR_PTR(-EAGAIN).

Thierry