From df4f94e810fc270db4baa8f4b35ef138246c7746 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 21 Aug 2018 11:11:38 +0100 Subject: [PATCH] drm/i915: Correct CSB probing for engine state dumper Since we no longer maintain our read position in the CSB pointers register, it always returns 0 and not where we last read up to. As a result the CSB probing in the state dumper starts from 0, either missing entries or showing stale one. Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20180821101138.15822-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_engine_cs.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 8628567d8f6e..1a34e8ff82d5 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -1345,20 +1345,19 @@ static void intel_engine_print_registers(const struct intel_engine_cs *engine, if (HAS_EXECLISTS(dev_priv)) { const u32 *hws = &engine->status_page.page_addr[I915_HWS_CSB_BUF0_INDEX]; - u32 ptr, read, write; unsigned int idx; + u8 read, write; drm_printf(m, "\tExeclist status: 0x%08x %08x\n", I915_READ(RING_EXECLIST_STATUS_LO(engine)), I915_READ(RING_EXECLIST_STATUS_HI(engine))); - ptr = I915_READ(RING_CONTEXT_STATUS_PTR(engine)); - read = GEN8_CSB_READ_PTR(ptr); - write = GEN8_CSB_WRITE_PTR(ptr); - drm_printf(m, "\tExeclist CSB read %d [%d cached], write %d [%d from hws], tasklet queued? %s (%s)\n", - read, execlists->csb_head, - write, - intel_read_status_page(engine, intel_hws_csb_write_index(engine->i915)), + read = execlists->csb_head; + write = READ_ONCE(*execlists->csb_write); + + drm_printf(m, "\tExeclist CSB read %d, write %d [mmio:%d], tasklet queued? %s (%s)\n", + read, write, + GEN8_CSB_WRITE_PTR(I915_READ(RING_CONTEXT_STATUS_PTR(engine))), yesno(test_bit(TASKLET_STATE_SCHED, &engine->execlists.tasklet.state)), enableddisabled(!atomic_read(&engine->execlists.tasklet.count))); @@ -1370,12 +1369,12 @@ static void intel_engine_print_registers(const struct intel_engine_cs *engine, write += GEN8_CSB_ENTRIES; while (read < write) { idx = ++read % GEN8_CSB_ENTRIES; - drm_printf(m, "\tExeclist CSB[%d]: 0x%08x [0x%08x in hwsp], context: %d [%d in hwsp]\n", + drm_printf(m, "\tExeclist CSB[%d]: 0x%08x [mmio:0x%08x], context: %d [mmio:%d]\n", idx, - I915_READ(RING_CONTEXT_STATUS_BUF_LO(engine, idx)), hws[idx * 2], - I915_READ(RING_CONTEXT_STATUS_BUF_HI(engine, idx)), - hws[idx * 2 + 1]); + I915_READ(RING_CONTEXT_STATUS_BUF_LO(engine, idx)), + hws[idx * 2 + 1], + I915_READ(RING_CONTEXT_STATUS_BUF_HI(engine, idx))); } rcu_read_lock(); -- 2.11.0