[Intel-gfx] [PATCH 2/2] drm/i915: Capture module params on hang

[Mika Kuoppala]

as it helps with bug triaging.

v2: Use PAGE_SIZE on alloc, don't spam to dmesg (Chris Wilson)

Suggested-by: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h       |  1 +
 drivers/gpu/drm/i915/i915_gpu_error.c | 31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0f00e58..c0ae57c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -339,6 +339,7 @@ struct drm_i915_error_state {
 	struct timeval time;
 
 	char error_msg[128];
+	char module_params_msg[1024];
 	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 89a2f3d..5f5735b 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -342,6 +342,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
 	err_printf(m, "Time: %ld s %ld us\n", error->time.tv_sec,
 		   error->time.tv_usec);
 	err_printf(m, "Kernel: " UTS_RELEASE "\n");
+	err_printf(m, "Module params: %s\n", error->module_params_msg);
 	max_hangcheck_score = 0;
 	for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
 		if (error->ring[i].hangcheck_score > max_hangcheck_score)
@@ -1258,6 +1259,34 @@ static void i915_error_capture_msg(struct drm_device *dev,
 		  wedged ? "reset" : "continue");
 }
 
+static void i915_error_capture_module_params(struct drm_i915_error_state *error)
+{
+	const struct module *m = THIS_MODULE;
+	int i, len;
+	char *buf;
+
+	if (!m)
+		return;
+
+	buf = kmalloc(PAGE_SIZE, GFP_ATOMIC);
+	if (buf == NULL)
+		return;
+
+	for (i = 0, len = 0; i < m->num_kp; i++) {
+		if (!m->kp[i].ops || !m->kp[i].ops->get ||
+		    m->kp[i].ops->get(buf, &m->kp[i]) <= 0)
+			continue;
+
+		len += scnprintf(error->module_params_msg + len,
+				 sizeof(error->module_params_msg) - len,
+				 "%s=%s ",
+				 m->kp[i].name,
+				 buf);
+	}
+
+	kfree(buf);
+}
+
 static void i915_capture_gen_state(struct drm_i915_private *dev_priv,
 				   struct drm_i915_error_state *error)
 {
@@ -1303,6 +1332,8 @@ void i915_capture_error_state(struct drm_device *dev, bool wedged,
 	error->display = intel_display_capture_error_state(dev);
 
 	i915_error_capture_msg(dev, error, wedged, error_msg);
+	i915_error_capture_module_params(error);
+
 	DRM_INFO("%s\n", error->error_msg);
 
 	spin_lock_irqsave(&dev_priv->gpu_error.lock, flags);
-- 
1.9.1