drm/i915: Show bounds of active request in the ring on GPU hang

Include the position of the active request in the ring, and display that
alongside the current RING registers (on a GPU hang).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161004201132.21801-6-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f8c66ee..4613f03 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -788,6 +788,9 @@ struct drm_i915_error_state {
                struct i915_address_space *vm;
                int num_requests;
 
+               /* position of active request inside the ring */
+               u32 rq_head, rq_post, rq_tail;
+
                /* our own tracking of ring head and tail */
                u32 cpu_ring_head;
                u32 cpu_ring_tail;

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 2bbab22..8b85efb 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -262,8 +262,9 @@ static void error_print_engine(struct drm_i915_error_state_buf *m,
 {
        err_printf(m, "%s command stream:\n", engine_str(ee->engine_id));
        err_printf(m, "  START: 0x%08x\n", ee->start);
-       err_printf(m, "  HEAD:  0x%08x\n", ee->head);
-       err_printf(m, "  TAIL:  0x%08x\n", ee->tail);
+       err_printf(m, "  HEAD:  0x%08x\n [0x%08x]", ee->head, ee->rq_head);
+       err_printf(m, "  TAIL:  0x%08x [0x%08x, 0x%08x]\n",
+                  ee->tail, ee->rq_post, ee->rq_tail);
        err_printf(m, "  CTL:   0x%08x\n", ee->ctl);
        err_printf(m, "  MODE:  0x%08x\n", ee->mode);
        err_printf(m, "  HWS:   0x%08x\n", ee->hws);
@@ -1230,6 +1231,10 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
                        error->simulated |=
                                request->ctx->flags & CONTEXT_NO_ERROR_CAPTURE;
 
+                       ee->rq_head = request->head;
+                       ee->rq_post = request->postfix;
+                       ee->rq_tail = request->tail;
+
                        ring = request->ring;
                        ee->cpu_ring_head = ring->head;
                        ee->cpu_ring_tail = ring->tail;