drm/i915/execlists: Ignore tracek for nop process_csb

Recording the frequent inspection of CSB head/tail when there is
expected to be no update adds noise to the debug trace. (Not entirely
useless, but since we know the sequence of function calls, we can
surmise the function was called -- so redundant.)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200209131922.180287-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 21385070ad15e939b2169ceca31ecf17380976f9..230470c58ec9617082b404763f5ea322c0c7062f 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -2248,7 +2248,6 @@ static void process_csb(struct intel_engine_cs *engine)
         */
        head = execlists->csb_head;
        tail = READ_ONCE(*execlists->csb_write);
-       ENGINE_TRACE(engine, "cs-irq head=%d, tail=%d\n", head, tail);
        if (unlikely(head == tail))
                return;
 
@@ -2262,6 +2261,7 @@ static void process_csb(struct intel_engine_cs *engine)
         */
        rmb();
 
+       ENGINE_TRACE(engine, "cs-irq head=%d, tail=%d\n", head, tail);
        do {
                bool promote;