From 582a6f90aa0d9103ab834b3a48a5bb7e4d07cac6 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 12 Sep 2019 10:29:32 +0100 Subject: [PATCH] drm/i915/execlists: Add a paranoid flush of the CSB pointers upon reset After a GPU reset, we need to drain all the CS events so that we have an accurate picture of the execlists state at the time of the reset. Be paranoid and force a read of the CSB write pointer from memory. Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20190912092933.4729-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_lrc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index dcdf7cf66e7e..dbc90da2341a 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -2359,6 +2359,10 @@ static void __execlists_reset(struct intel_engine_cs *engine, bool stalled) struct i915_request *rq; u32 *regs; + mb(); /* paranoia: read the CSB pointers from after the reset */ + clflush(execlists->csb_write); + mb(); + process_csb(engine); /* drain preemption events */ /* Following the reset, we need to reload the CSB read/write pointers */ -- 2.45.2