From: Chris Wilson Date: Mon, 5 Feb 2018 15:24:31 +0000 (+0000) Subject: drm/i915: Skip post-reset request emission if the engine is not idle X-Git-Tag: v5.15~6763^2~28^2~1882 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=01b8fdc5222007bdfc905941173f82576898a7f7;p=platform%2Fkernel%2Flinux-starfive.git drm/i915: Skip post-reset request emission if the engine is not idle Since commit 7b6da818d86f ("drm/i915: Restore the kernel context after a GPU reset on an idle engine") we submit a request following the engine reset. The intent is that we don't submit a request if the engine is busy (as it will restart active by itself) but we only checked to see if there were remaining requests in flight on the hardware and skipped checking to see if there were any ready requests that would be immediately submitted on restart (the same time as our new request would be). Having convinced the engine to appear idle in the previous patch, we can use intel_engine_is_idle() as a better test to only submit a new request if there are no pending requests. As it happens, this is tripping up igt/drv_selftest/live_hangcheck in CI as we overfill the kernel_context ringbuffer trigger an infinite recursion from within the reset. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104786 References: 7b6da818d86f ("drm/i915: Restore the kernel context after a GPU reset on an idle engine") Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Joonas Lahtinen Cc: Michel Thierry Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20180205152431.12163-4-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index f3cc40a..1632f18 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3133,7 +3133,7 @@ void i915_gem_reset(struct drm_i915_private *dev_priv) * an incoherent read by the CS (presumably stale TLB). An * empty request appears sufficient to paper over the glitch. */ - if (list_empty(&engine->timeline->requests)) { + if (intel_engine_is_idle(engine)) { struct drm_i915_gem_request *rq; rq = i915_gem_request_alloc(engine,