Re: kern/49838: radeon drm2 kernel panic

[Tobias Nygren <tnn%NetBSD.org@localhost>]

The following reply was made to PR kern/49838; it has been noted by GNATS.

From: Tobias Nygren <tnn%NetBSD.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/49838: radeon drm2 kernel panic
Date: Mon, 13 Apr 2015 18:28:20 +0200

 > teapot crashes after a few seconds with the following, sometimes takes kernel with it:
 
 Found a workaround for the teapot segfault. the r600 driver in MesaLib
 10.x runs a separate worker thread for DRM_IOCTL_RADEON_CS if it
 detects multiprocessor hardware. It gets a segfault when the worker
 thread runs it's ioctl while the other thread loads things into the
 graphics pipeline. Note sure if this is a Mesa or kernel bug.
 
 Removing this code from Mesa's
 radeon_drm_winsys.c:radeon_drm_winsys_create() makes it not crash any
 more.
 
 -   if (ws->num_cpus > 1 && debug_get_option_thread())
 -       ws->thread = pipe_thread_create(radeon_drm_cs_emit_ioctl, ws);