Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 83c31783 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Dump the ringbuffer of the active request for debugging 



Sometimes we need to see what instructions we emitted for a request to
try and gather a glimmer of insight into what the GPU is doing when it
stops responding.

v2: Move ring dumping into its own routine

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180614122150.17552-1-chris@chris-wilson.co.uk


Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
parent 856e1b17

drivers/gpu/drm/i915/intel_engine_cs.c

+36 −5
Original line number Diff line number Diff line
@@ -1394,6 +1394,39 @@ static void intel_engine_print_registers(const struct intel_engine_cs *engine, 
	}

}



static void print_request_ring(struct drm_printer *m, struct i915_request *rq)

{

	void *ring;

	int size;



	drm_printf(m,

		   "[head %04x, postfix %04x, tail %04x, batch 0x%08x_%08x]:\n",

		   rq->head, rq->postfix, rq->tail,

		   rq->batch ? upper_32_bits(rq->batch->node.start) : ~0u,

		   rq->batch ? lower_32_bits(rq->batch->node.start) : ~0u);



	size = rq->tail - rq->head;

	if (rq->tail < rq->head)

		size += rq->ring->size;



	ring = kmalloc(size, GFP_ATOMIC);

	if (ring) {

		const void *vaddr = rq->ring->vaddr;

		unsigned int head = rq->head;

		unsigned int len = 0;



		if (rq->tail < head) {

			len = rq->ring->size - head;

			memcpy(ring, vaddr + head, len);

			head = 0;

		}

		memcpy(ring + len, vaddr + head, size - len);



		hexdump(m, ring, size);

		kfree(ring);

	}

}



void intel_engine_dump(struct intel_engine_cs *engine,

		       struct drm_printer *m,

		       const char *header, ...)
@@ -1444,11 +1477,7 @@ void intel_engine_dump(struct intel_engine_cs *engine, 
	rq = i915_gem_find_active_request(engine);

	if (rq) {

		print_request(m, rq, "\t\tactive ");

		drm_printf(m,

			   "\t\t[head %04x, postfix %04x, tail %04x, batch 0x%08x_%08x]\n",

			   rq->head, rq->postfix, rq->tail,

			   rq->batch ? upper_32_bits(rq->batch->node.start) : ~0u,

			   rq->batch ? lower_32_bits(rq->batch->node.start) : ~0u);



		drm_printf(m, "\t\tring->start:  0x%08x\n",

			   i915_ggtt_offset(rq->ring->vma));

		drm_printf(m, "\t\tring->head:   0x%08x\n",
@@ -1459,6 +1488,8 @@ void intel_engine_dump(struct intel_engine_cs *engine, 
			   rq->ring->emit);

		drm_printf(m, "\t\tring->space:  0x%08x\n",

			   rq->ring->space);



		print_request_ring(m, rq);

	}



	rcu_read_unlock();