[Intel-gfx] [PATCH 2/2] drm/i915: Add the last written reg to error state

[Ben Widawsky]

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_drv.h       |  1 +
 drivers/gpu/drm/i915/i915_gpu_error.c | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6fa22db..49bc296 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -323,6 +323,7 @@ struct drm_i915_error_state {
 	struct timeval time;
 
 	char error_msg[128];
+	u32 last_written[NR_CPUS];
 	u32 reset_count;
 	u32 suspend_count;
 
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 2c87a79..f7737c5 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -356,6 +356,9 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
 				   error->ring[i].pid);
 		}
 	}
+	for_each_possible_cpu(i)
+		err_printf(m, "Last written register (cpu=%d): 0x%08x\n",
+			   i, error->last_written[i]);
 	err_printf(m, "Reset count: %u\n", error->reset_count);
 	err_printf(m, "Suspend count: %u\n", error->suspend_count);
 	err_printf(m, "PCI ID: 0x%04x\n", dev->pdev->device);
@@ -1253,6 +1256,13 @@ static void i915_error_capture_msg(struct drm_device *dev,
 		  wedged ? "reset" : "continue");
 }
 
+static void i915_capture_cpu_state(struct drm_i915_error_state *error)
+{
+	int cpu;
+	for_each_possible_cpu(cpu)
+		error->last_written[cpu] = per_cpu(i915_last_written, cpu);
+}
+
 static void i915_capture_gen_state(struct drm_i915_private *dev_priv,
 				   struct drm_i915_error_state *error)
 {
@@ -1286,6 +1296,7 @@ void i915_capture_error_state(struct drm_device *dev, bool wedged,
 
 	kref_init(&error->ref);
 
+	i915_capture_cpu_state(error);
 	i915_capture_gen_state(dev_priv, error);
 	i915_capture_reg_state(dev_priv, error);
 	i915_gem_capture_buffers(dev_priv, error);
-- 
2.3.0