From 36362ad3b64acd5e4d438db480bdb80a4ff75eb2 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Tue, 1 Jul 2014 11:17:41 -0700 Subject: [PATCH] drm/i915/error: Check the potential ctx obj's vm The bound list is global (all objects which back the VMAs are stored here). Recently the BUG() in the offset lookup was demoted to a WARN, but the fault actually lies in the caller, here. This bug has existed since the initial introduction of PPGTT (however, it was fixed in unmerged patches to fix up the error state). Note: The reason for the BUG_ON to WARN_ON demotion was _not_ to duct-tape over this bug here but another but triggerable without ppgtt. See the commit for details: commit f25748ea7342bcc44866befcbf0222cd1d89d851 Author: Daniel Vetter Date: Tue Jun 17 22:34:38 2014 +0200 drm/i915: Don't BUG_ON in i915_gem_obj_offset A WARN_ON is perfectly fine. The BUG in here seems to be the cause behind hard-hangs when I cat the i915_gem_pageflip debugfs file (which calls this from an irq spinlock). But only while running a full igt run after a while. I still need to root cause the underlying issue. I'll also start reject patches which add new BUG_ON but don't come with a really good justification for it. The general rule really should be to just WARN and hope the driver survives for long enough. v2: Make the WARN a bit more useful per Chris' suggestion. Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter Signed-off-by: Ben Widawsky [danvet: Clarfy that the WARN_ON (former BUG_ON) in ggtt_offset caught more than just this bug fixed in this patch here.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gpu_error.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index 45b6191efb58..9faebbc22191 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -920,6 +920,9 @@ static void i915_gem_record_active_context(struct intel_engine_cs *ring, return; list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) { + if (!i915_gem_obj_ggtt_bound(obj)) + continue; + if ((error->ccid & PAGE_MASK) == i915_gem_obj_ggtt_offset(obj)) { ering->ctx = i915_error_ggtt_object_create(dev_priv, obj); break; -- 2.39.5