i965: Properly return *RESET* status in glGetGraphicsResetStatusARB
The glGetGraphicsResetStatusARB from ARB_robustness extension always returns GUILTY_CONTEXT_RESET_ARB and never returns NO_ERROR for guilty context with LOSE_CONTEXT_ON_RESET_ARB strategy. This is because Mesa returns GUILTY_CONTEXT_RESET_ARB if batch_active !=0 whereas kernel driver never reset batch_active and this variable always > 0 for guilty context. The same behaviour also can be observed for batch_pending and INNOCENT_CONTEXT_RESET_ARB. But ARB_robustness spec says: If a reset status other than NO_ERROR is returned and subsequent calls return NO_ERROR, the context reset was encountered and completed. If a reset status is repeatedly returned, the context may be in the process of resetting. 8. How should the application react to a reset context event? RESOLVED: For this extension, the application is expected to query the reset status until NO_ERROR is returned. If a reset is encountered, at least one *RESET* status will be returned. Once NO_ERROR is encountered, the application can safely destroy the old context and create a new one. The main problem is the context may be in the process of resetting and in this case a reset status should be repeatedly returned. But looks like the kernel driver returns nonzero active/pending only if the context reset has already been encountered and completed. For this reason the *RESET* status cannot be repeatedly returned and should be returned only once. The reset_count and brw->reset_count variables can be used to control that glGetGraphicsResetStatusARB returns *RESET* status only once for each context. Note the i915 triggers reset_count twice which allows to return correct reset count immediately after active/pending have been incremented. v2 (idr): Trivial reformatting of comments. Signed-off-by:Pavel Popov <pavel.e.popov@intel.com> Reviewed-by:
Ian Romanick <ian.d.romanick@intel.com> Cc: "10.1 10.2" <mesa-stable@lists.freedesktop.org>
Please register or sign in to comment