From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman Subject: [PATCH 4.4 217/342] drm/i915: Restore inhibiting the load of the default context To: Cc: Greg Kroah-Hartman , , Chris Wilson , Michel Thierry , Mika Kuoppala , Daniel Vetter , Jani Nikula Message-Id: <20160301234534.944154735@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> Date: Tue, 01 Mar 2016 23:54:57 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Wilson commit 06ef83a705a98da63797a5a570220b6ca36febd4 upstream. 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 6702cf16e0ba8b0129f5aa1b6609d4e9c70bc13b [v4.1] Author: Ben Widawsky 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 Cc: Michel Thierry Cc: Mika Kuoppala Cc: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1448630935-27377-1-git-send-email-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala [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 (cherry picked from commit 42f1cae8c079bcceb3cff079fddc3ff8852c788f) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_gem_context.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -340,6 +340,10 @@ void i915_gem_context_reset(struct drm_d 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; } } @@ -708,7 +712,7 @@ static int do_switch(struct drm_i915_gem 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