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: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180614122150.17552-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
This commit is contained in:
Chris Wilson 2018-06-14 13:21:50 +01:00
parent 856e1b1756
commit 83c317832e

View File

@ -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();