On Tue, 3 Jan 2012 22:49:52 +0100, Daniel Vetter <daniel.vetter at ffwll.ch> wrote: > Nope, current hangcheck blows up, and we have an i-g-t testcase for it > (which the commit msg clearly states). There are also numerous bug > reports where a dying gpu results in tons of > WARN_ON(!mutex_locked(dev->struct_mutex)) noise in dmesg (which drowns > out the gpu hang warning). The locking change fixes this. Ah, ok, that makes sense. Of course, hangcheck *could* have just taken struct_mutex were it run in a suitable context. > The patch adds the required locking to i915_reset. No, the spinlock protects the forcewake_count access and not the actual register access, which leaves all kinds of potential for races in threads not also holding struct_mutex while accessing registers. If you want a spinlock to protect the register access, it must surround the whole operation. -- keith.packard at intel.com -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 827 bytes Desc: not available URL: <http://lists.freedesktop.org/archives/intel-gfx/attachments/20120103/126bbf39/attachment.pgp>
