drm/i915: Restore inhibiting the load of the default context

Following a GPU reset, we may leave the context in a poorly defined
state, and reloading from that context will leave the GPU flummoxed. For
secondary contexts, this will lead to that context being banned - but
currently it is also causing the default context to become banned,
leading to turmoil in the shared state.

This is a regression from

commit 6702cf16e0 [v4.1]
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Mon Mar 16 16:00:58 2015 +0000

    drm/i915: Initialize all contexts

which quietly introduced the removal of the MI_RESTORE_INHIBIT on the
default context.

v2: Mark the global default context as uninitialized on GPU reset so
that the context-local workarounds are reloaded upon re-enabling.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1448630935-27377-1-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: stable@vger.kernel.org
[danvet: This seems to fix a gpu hand on after the first resume,
resulting in any future suspend operation failing with -EIO because
the gpu seems to be in a funky state. Somehow this patch fixes that.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 42f1cae8c0)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Chris Wilson 2015-11-27 13:28:55 +00:00 committed by Jani Nikula
parent 5751d0f6c5
commit 06ef83a705
1 changed files with 5 additions and 1 deletions

View File

@ -347,6 +347,10 @@ void i915_gem_context_reset(struct drm_device *dev)
i915_gem_context_unreference(lctx);
ring->last_context = NULL;
}
/* Force the GPU state to be reinitialised on enabling */
if (ring->default_context)
ring->default_context->legacy_hw_ctx.initialized = false;
}
}
@ -715,7 +719,7 @@ static int do_switch(struct drm_i915_gem_request *req)
if (ret)
goto unpin_out;
if (!to->legacy_hw_ctx.initialized) {
if (!to->legacy_hw_ctx.initialized || i915_gem_context_is_default(to)) {
hw_flags |= MI_RESTORE_INHIBIT;
/* NB: If we inhibit the restore, the context is not allowed to
* die because future work may end up depending on valid address