[PATCH 017/131] drm/i915: Record the RING_MODE register for post-mortem debugging

[Chris Wilson]

Just another useful register to inspect following a GPU hang.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_drv.h       | 1 +
 drivers/gpu/drm/i915/i915_gpu_error.c | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b26f86b583a8..8596adec2959 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -534,6 +534,7 @@ struct drm_i915_error_state {
 		u32 tail;
 		u32 head;
 		u32 ctl;
+		u32 mode;
 		u32 hws;
 		u32 ipeir;
 		u32 ipehr;
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 6078f47d4bc0..29068b37c111 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -237,6 +237,8 @@ static void error_print_engine(struct drm_i915_error_state_buf *m,
 	err_printf(m, "  HEAD:  0x%08x\n", ee->head);
 	err_printf(m, "  TAIL:  0x%08x\n", ee->tail);
 	err_printf(m, "  CTL:   0x%08x\n", ee->ctl);
+	err_printf(m, "  MODE:  0x%08x [idle? %d]\n",
+		   ee->mode, !!(ee->mode & MODE_IDLE));
 	err_printf(m, "  HWS:   0x%08x\n", ee->hws);
 	err_printf(m, "  ACTHD: 0x%08x %08x\n",
 		   (u32)(ee->acthd>>32), (u32)ee->acthd);
@@ -979,6 +981,8 @@ static void error_record_engine_registers(struct drm_i915_error_state *error,
 	ee->head = I915_READ_HEAD(engine);
 	ee->tail = I915_READ_TAIL(engine);
 	ee->ctl = I915_READ_CTL(engine);
+	if (INTEL_GEN(dev_priv) > 2)
+		ee->mode = I915_READ_MODE(engine);
 
 	if (I915_NEED_GFX_HWS(dev_priv)) {
 		i915_reg_t mmio;
-- 
2.8.1