4 files changed, 36 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 7466e739887d..68592b0de874 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -50,6 +50,21 @@
 #include <linux/pm_runtime.h>
 #include <linux/oom.h>
 
+static unsigned int i915_load_fail_count;
+
+bool __i915_inject_load_failure(const char *func, int line)
+{
+        if (i915_load_fail_count >= i915.inject_load_failure)
+                return false;
+
+        if (++i915_load_fail_count == i915.inject_load_failure) {
+                DRM_INFO("Injecting failure at checkpoint %u [%s:%d]\n",
+                         i915.inject_load_failure, func, line);
+                return true;
+        }
+
+        return false;
+}
 
 static int i915_getparam(struct drm_device *dev, void *data,
                          struct drm_file *file_priv)
@@ -370,6 +385,9 @@ static int i915_load_modeset_init(struct drm_device *dev)
         struct drm_i915_private *dev_priv = dev->dev_private;
         int ret;
 
+        if (i915_inject_load_failure())
+                return -ENODEV;
+
         ret = intel_bios_init(dev_priv);
         if (ret)
                 DRM_INFO("failed to find VBIOS tables\n");
@@ -951,6 +969,9 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
         struct intel_device_info *device_info;
         int ret = 0;
 
+        if (i915_inject_load_failure())
+                return -ENODEV;
+
         dev_priv->dev = dev;
 
         /* Setup the write-once "constant" device info */
@@ -1065,6 +1086,9 @@ static int i915_driver_init_mmio(struct drm_i915_private *dev_priv)
         struct drm_device *dev = dev_priv->dev;
         int ret;
 
+        if (i915_inject_load_failure())
+                return -ENODEV;
+
         if (i915_get_bridge_dev(dev))
                 return -EIO;
 
@@ -1108,6 +1132,9 @@ static int i915_driver_init_hw(struct drm_i915_private *dev_priv)
         uint32_t aperture_size;
         int ret;
 
+        if (i915_inject_load_failure())
+                return -ENODEV;
+
         intel_device_info_runtime_init(dev);
 
         ret = i915_gem_gtt_init(dev);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e6d4b1ce130e..00c41a4bde2a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -98,6 +98,10 @@
 #define I915_STATE_WARN_ON(x)                                           \
         I915_STATE_WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
 
+bool __i915_inject_load_failure(const char *func, int line);
+#define i915_inject_load_failure() \
+        __i915_inject_load_failure(__func__, __LINE__)
+
 static inline const char *yesno(bool v)
 {
         return v ? "yes" : "no";
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 97691f1f679c..1779f02e6df8 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -57,6 +57,7 @@ struct i915_params i915 __read_mostly = {
         .enable_guc_submission = false,
         .guc_log_level = -1,
         .enable_dp_mst = true,
+        .inject_load_failure = 0,
 };
 
 module_param_named(modeset, i915.modeset, int, 0400);
@@ -206,3 +207,6 @@ MODULE_PARM_DESC(guc_log_level,
 module_param_named_unsafe(enable_dp_mst, i915.enable_dp_mst, bool, 0600);
 MODULE_PARM_DESC(enable_dp_mst,
         "Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
+module_param_named_unsafe(inject_load_failure, i915.inject_load_failure, uint, 0400);
+MODULE_PARM_DESC(inject_load_failure,
+        "Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)");
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index 87153b0199cd..02bc27804291 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -49,6 +49,7 @@ struct i915_params {
         int use_mmio_flip;
         int mmio_debug;
         int edp_vswing;
+        unsigned int inject_load_failure;
         /* leave bools at the end to not create holes */
         bool enable_hangcheck;
         bool fastboot;