We have been carrying a (rather poor) patch for an issue we identified in the DRM driver. This issue is triggered when a DRM device is initialising and userspace attempts to open it, typically in response to the sysfs device added event. Basically we allocate the minor numbers making the device available, and then call the drm load callback. Until this completes the device is really not ready and these early opens typically lead to oopses. We have been using the following patch to avoid this by marking the minors as in error until the load method has completed. This avoids the early open by simply erroring out the opens with EAGAIN. Obviously we should be delaying the open until the load method complete. I include the existing patch for completness (it is not really ready for merging) to illustrate the issue. I think it is logical that the wait should simply be delayed until the load has completed. I am proposing to include a wait queue associated with the idr cache for the drm minors which we can use to allow open callers to wait_event_interruptible() on. I'll be putting together a prototype shortly and will follow up with it. Thoughts? -apw Andy Whitcroft (1): drm -- stop early access to drm devices drivers/gpu/drm/drm_fops.c | 8 ++++++-- drivers/gpu/drm/drm_pci.c | 4 ++++ drivers/gpu/drm/drm_platform.c | 4 ++++ drivers/gpu/drm/drm_stub.c | 2 +- 4 files changed, 15 insertions(+), 3 deletions(-) -- 1.7.9.5 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
