From: Imre Deak Date: Wed, 16 Mar 2016 11:39:08 +0000 (+0200) Subject: drm/i915: Add fault injection support X-Git-Tag: v4.7-rc1~77^2~66^2~59 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4fec15d1bd8352b6fc1edd71ae35ab138df010fc;p=karo-tx-linux.git drm/i915: Add fault injection support Add support for forcing an error at selected places in the driver. As an example add 4 options to fail during driver loading. Requested by Chris. v2: - Add fault point for modeset initialization - Print debug message when injecting an error v3: - Rename inject_fault to inject_load_failure, rename the related macros and helper accordingly (Chris) - Use a counter instead of a mask to identify the failure point (Daniel) - Mark the module option as _unsafe and keep i915_params ordered (Joonas) v4: - Rebase on latest -nightly v5: - Use DRM_INFO instead of DRM_DEBUG_DRIVER, making it clearer in CI reports that a following error message is expected (IRC r-b from Chris on v5) CC: Chris Wilson CC: Daniel Vetter CC: Joonas Lahtinen Signed-off-by: Imre Deak Reviewed-by: Chris Wilson --- 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 #include +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;