Re: [PATCH 1/1] drm/i915: switch to use kernel standard error injection

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 19 Nov 2025, Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com> wrote:
> Switch error injection testing from i915_inject_probe_failure
> to ALLOW_ERROR_INJECTION. Here taken out calls to
> i915_inject_probe_failure and changed to use
> ALLOW_ERROR_INJECTION for the same functions.
>
> Below functions are dropped from testing since I
> couldn't hit those at module bind time, testing
> these would just fail the tests. To include these
> in test would need to find way to cause resetting in i915
> which would trigger these:
>
> intel_gvt_init
> intel_wopcm_init
> intel_uc_fw_upload
> intel_gt_init with expected -EIO (-EINVAL is tested)
> lrc_init_wa_ctx
> intel_huc_auth
> guc_check_version_range
> intel_uc_fw_fetch
> uc_fw_xfer
> __intel_uc_reset_hw
> guc_enable_communication
> uc_init_wopcm
> ..and all stages of __force_fw_fetch_failures
>
> Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>

This obviously isn't 1:1 with the existing implementation. Some error
paths are left out. There's no suppression of messages after a fault has
been injected.

I don't care.

The coverage can be expanded and new faults injected afterwards.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


> ---
>  .../gpu/drm/i915/display/intel_connector.c    | 14 +----
>  .../drm/i915/display/intel_display_driver.c   |  5 +-
>  drivers/gpu/drm/i915/gt/intel_engine_cs.c     |  4 +-
>  drivers/gpu/drm/i915/gt/intel_gt.c            |  9 +--
>  drivers/gpu/drm/i915/gt/intel_gt_print.h      |  5 +-
>  drivers/gpu/drm/i915/gt/intel_lrc.c           |  4 --
>  drivers/gpu/drm/i915/gt/intel_wopcm.c         |  3 -
>  drivers/gpu/drm/i915/gt/intel_wopcm.h         |  1 +
>  drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c     |  8 +--
>  drivers/gpu/drm/i915/gt/uc/intel_huc.c        |  4 --
>  drivers/gpu/drm/i915/gt/uc/intel_uc.c         | 17 +-----
>  drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c      | 60 +------------------
>  drivers/gpu/drm/i915/i915_driver.c            | 12 +---
>  drivers/gpu/drm/i915/i915_params.c            |  5 --
>  drivers/gpu/drm/i915/i915_params.h            |  1 -
>  drivers/gpu/drm/i915/i915_pci.c               |  6 +-
>  drivers/gpu/drm/i915/i915_utils.c             | 30 +---------
>  drivers/gpu/drm/i915/i915_utils.h             | 22 +------
>  drivers/gpu/drm/i915/intel_gvt.c              |  3 -
>  drivers/gpu/drm/i915/intel_uncore.c           |  4 +-
>  20 files changed, 18 insertions(+), 199 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_connector.c b/drivers/gpu/drm/i915/display/intel_connector.c
> index 913d90a7a508..c128bc4215c4 100644
> --- a/drivers/gpu/drm/i915/display/intel_connector.c
> +++ b/drivers/gpu/drm/i915/display/intel_connector.c
> @@ -156,27 +156,17 @@ void intel_connector_destroy(struct drm_connector *connector)
>  int intel_connector_register(struct drm_connector *_connector)
>  {
>  	struct intel_connector *connector = to_intel_connector(_connector);
> -	struct drm_i915_private *i915 = to_i915(_connector->dev);
>  	int ret;
>  
>  	ret = intel_panel_register(connector);
>  	if (ret)
> -		goto err;
> -
> -	if (i915_inject_probe_failure(i915)) {
> -		ret = -EFAULT;
> -		goto err_panel;
> -	}
> +		return ret;
>  
>  	intel_connector_debugfs_add(connector);
>  
>  	return 0;
> -
> -err_panel:
> -	intel_panel_unregister(connector);
> -err:
> -	return ret;
>  }
> +ALLOW_ERROR_INJECTION(intel_connector_register, ERRNO);
>  
>  void intel_connector_unregister(struct drm_connector *_connector)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c b/drivers/gpu/drm/i915/display/intel_display_driver.c
> index 7e000ba3e08b..2fe57feda1c7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_driver.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
> @@ -199,12 +199,8 @@ void intel_display_driver_early_probe(struct intel_display *display)
>  /* part #1: call before irq install */
>  int intel_display_driver_probe_noirq(struct intel_display *display)
>  {
> -	struct drm_i915_private *i915 = to_i915(display->drm);
>  	int ret;
>  
> -	if (i915_inject_probe_failure(i915))
> -		return -ENODEV;
> -
>  	if (HAS_DISPLAY(display)) {
>  		ret = drm_vblank_init(display->drm,
>  				      INTEL_NUM_PIPES(display));
> @@ -317,6 +313,7 @@ int intel_display_driver_probe_noirq(struct intel_display *display)
>  
>  	return ret;
>  }
> +ALLOW_ERROR_INJECTION(intel_display_driver_probe_noirq, ERRNO);
>  
>  static void set_display_access(struct intel_display *display,
>  			       bool any_task_allowed,
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> index b721bbd23356..98a3a7a9de50 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> @@ -963,9 +963,6 @@ int intel_engines_init_mmio(struct intel_gt *gt)
>  	drm_WARN_ON(&i915->drm, engine_mask &
>  		    GENMASK(BITS_PER_TYPE(mask) - 1, I915_NUM_ENGINES));
>  
> -	if (i915_inject_probe_failure(i915))
> -		return -ENODEV;
> -
>  	for (class = 0; class < MAX_ENGINE_CLASS + 1; ++class) {
>  		setup_logical_ids(gt, logical_ids, class);
>  
> @@ -1007,6 +1004,7 @@ int intel_engines_init_mmio(struct intel_gt *gt)
>  	intel_engines_free(gt);
>  	return err;
>  }
> +ALLOW_ERROR_INJECTION(intel_engines_init_mmio, ERRNO);
>  
>  void intel_engine_init_execlists(struct intel_engine_cs *engine)
>  {
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
> index 3d3b1ba76e2b..ac527d878820 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
> @@ -686,10 +686,6 @@ int intel_gt_init(struct intel_gt *gt)
>  {
>  	int err;
>  
> -	err = i915_inject_probe_error(gt->i915, -ENODEV);
> -	if (err)
> -		return err;
> -
>  	intel_gt_init_workarounds(gt);
>  
>  	/*
> @@ -740,10 +736,6 @@ int intel_gt_init(struct intel_gt *gt)
>  	if (err)
>  		goto err_gt;
>  
> -	err = i915_inject_probe_error(gt->i915, -EIO);
> -	if (err)
> -		goto err_gt;
> -
>  	intel_uc_init_late(&gt->uc);
>  
>  	intel_migrate_init(&gt->migrate, gt);
> @@ -766,6 +758,7 @@ int intel_gt_init(struct intel_gt *gt)
>  	intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
>  	return err;
>  }
> +ALLOW_ERROR_INJECTION(intel_gt_init, ERRNO);
>  
>  void intel_gt_driver_remove(struct intel_gt *gt)
>  {
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_print.h b/drivers/gpu/drm/i915/gt/intel_gt_print.h
> index 7fdc78c79273..48f0afd05fd8 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_print.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_print.h
> @@ -36,10 +36,7 @@
>  
>  #define gt_probe_error(_gt, _fmt, ...) \
>  	do { \
> -		if (i915_error_injected()) \
> -			gt_dbg(_gt, _fmt, ##__VA_ARGS__); \
> -		else \
> -			gt_err(_gt, _fmt, ##__VA_ARGS__); \
> +		gt_err(_gt, _fmt, ##__VA_ARGS__); \
>  	} while (0)
>  
>  #define gt_WARN(_gt, _condition, _fmt, ...) \
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index e8927ad49142..d36e543e98df 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -1911,10 +1911,6 @@ void lrc_init_wa_ctx(struct intel_engine_cs *engine)
>  	__i915_gem_object_flush_map(wa_ctx->vma->obj, 0, batch_ptr - batch);
>  	__i915_gem_object_release_map(wa_ctx->vma->obj);
>  
> -	/* Verify that we can handle failure to setup the wa_ctx */
> -	if (!err)
> -		err = i915_inject_probe_error(engine->i915, -ENODEV);
> -
>  err_unpin:
>  	if (err)
>  		i915_vma_unpin(wa_ctx->vma);
> diff --git a/drivers/gpu/drm/i915/gt/intel_wopcm.c b/drivers/gpu/drm/i915/gt/intel_wopcm.c
> index 1b26ff6488b3..602e088fe045 100644
> --- a/drivers/gpu/drm/i915/gt/intel_wopcm.c
> +++ b/drivers/gpu/drm/i915/gt/intel_wopcm.c
> @@ -253,9 +253,6 @@ void intel_wopcm_init(struct intel_wopcm *wopcm)
>  	GEM_BUG_ON(huc_fw_size >= wopcm_size);
>  	GEM_BUG_ON(ctx_rsvd + WOPCM_RESERVED_SIZE >= wopcm_size);
>  
> -	if (i915_inject_probe_failure(i915))
> -		return;
> -
>  	if (__wopcm_regs_locked(gt->uncore, &guc_wopcm_base, &guc_wopcm_size)) {
>  		drm_dbg(&i915->drm, "GuC WOPCM is already locked [%uK, %uK)\n",
>  			guc_wopcm_base / SZ_1K, guc_wopcm_size / SZ_1K);
> diff --git a/drivers/gpu/drm/i915/gt/intel_wopcm.h b/drivers/gpu/drm/i915/gt/intel_wopcm.h
> index d2038b6de5e7..73dc6ff3a894 100644
> --- a/drivers/gpu/drm/i915/gt/intel_wopcm.h
> +++ b/drivers/gpu/drm/i915/gt/intel_wopcm.h
> @@ -56,4 +56,5 @@ static inline u32 intel_wopcm_guc_size(struct intel_wopcm *wopcm)
>  void intel_wopcm_init_early(struct intel_wopcm *wopcm);
>  void intel_wopcm_init(struct intel_wopcm *wopcm);
>  
> +int intel_wopcm_init_inject_failure(void);
>  #endif
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> index 2c651ec024ef..f1e53312ed90 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
> @@ -266,10 +266,6 @@ int intel_guc_ct_init(struct intel_guc_ct *ct)
>  	u32 *cmds;
>  	int err;
>  
> -	err = i915_inject_probe_error(guc_to_i915(guc), -ENXIO);
> -	if (err)
> -		return err;
> -
>  	GEM_BUG_ON(ct->vma);
>  
>  	blob_size = 2 * CTB_DESC_SIZE + CTB_H2G_BUFFER_SIZE + CTB_G2H_BUFFER_SIZE;
> @@ -306,6 +302,7 @@ int intel_guc_ct_init(struct intel_guc_ct *ct)
>  
>  	return 0;
>  }
> +ALLOW_ERROR_INJECTION(intel_guc_ct_init, ERRNO);
>  
>  /**
>   * intel_guc_ct_fini - Fini buffer-based communication
> @@ -1394,9 +1391,6 @@ static void ct_dead_ct_worker_func(struct work_struct *w)
>  	if (ct->dead_ct_reported)
>  		return;
>  
> -	if (i915_error_injected())
> -		return;
> -
>  	ct->dead_ct_reported = true;
>  
>  	guc_info(guc, "CTB is dead - reason=0x%X\n", ct->dead_ct_reason);
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_huc.c b/drivers/gpu/drm/i915/gt/uc/intel_huc.c
> index 456d3372eef8..f3249b98c992 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_huc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_huc.c
> @@ -541,10 +541,6 @@ int intel_huc_auth(struct intel_huc *huc, enum intel_huc_authentication_type typ
>  	if (intel_huc_is_authenticated(huc, type))
>  		return -EEXIST;
>  
> -	ret = i915_inject_probe_error(gt->i915, -ENXIO);
> -	if (ret)
> -		goto fail;
> -
>  	switch (type) {
>  	case INTEL_HUC_AUTH_BY_GUC:
>  		ret = intel_guc_auth_huc(guc, intel_guc_ggtt_offset(guc, huc->fw.rsa_data));
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> index 4a3493e8d433..bd07c72a66fc 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> @@ -60,10 +60,6 @@ static int __intel_uc_reset_hw(struct intel_uc *uc)
>  	int ret;
>  	u32 guc_status;
>  
> -	ret = i915_inject_probe_error(gt->i915, -ENXIO);
> -	if (ret)
> -		return ret;
> -
>  	ret = intel_reset_guc(gt);
>  	if (ret) {
>  		gt_err(gt, "Failed to reset GuC, ret = %d\n", ret);
> @@ -220,15 +216,10 @@ static void guc_handle_mmio_msg(struct intel_guc *guc)
>  static int guc_enable_communication(struct intel_guc *guc)
>  {
>  	struct intel_gt *gt = guc_to_gt(guc);
> -	struct drm_i915_private *i915 = gt->i915;
>  	int ret;
>  
>  	GEM_BUG_ON(intel_guc_ct_enabled(&guc->ct));
>  
> -	ret = i915_inject_probe_error(i915, -ENXIO);
> -	if (ret)
> -		return ret;
> -
>  	ret = intel_guc_ct_enable(&guc->ct);
>  	if (ret)
>  		return ret;
> @@ -323,9 +314,6 @@ static int __uc_init(struct intel_uc *uc)
>  	if (!intel_uc_uses_guc(uc))
>  		return 0;
>  
> -	if (i915_inject_probe_failure(uc_to_gt(uc)->i915))
> -		return -ENOMEM;
> -
>  	ret = intel_guc_init(guc);
>  	if (ret)
>  		return ret;
> @@ -338,6 +326,7 @@ static int __uc_init(struct intel_uc *uc)
>  
>  	return 0;
>  }
> +ALLOW_ERROR_INJECTION(__uc_init, ERRNO);
>  
>  static void __uc_fini(struct intel_uc *uc)
>  {
> @@ -381,10 +370,6 @@ static int uc_init_wopcm(struct intel_uc *uc)
>  	GEM_BUG_ON(!(size & GUC_WOPCM_SIZE_MASK));
>  	GEM_BUG_ON(size & ~GUC_WOPCM_SIZE_MASK);
>  
> -	err = i915_inject_probe_error(gt->i915, -ENXIO);
> -	if (err)
> -		return err;
> -
>  	mask = GUC_WOPCM_SIZE_MASK | GUC_WOPCM_SIZE_LOCKED;
>  	err = intel_uncore_write_and_verify(uncore, GUC_WOPCM_SIZE, size, mask,
>  					    size | GUC_WOPCM_SIZE_LOCKED);
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> index e848a04a80dc..fd04fe892c28 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> @@ -542,43 +542,6 @@ void intel_uc_fw_init_early(struct intel_uc_fw *uc_fw,
>  				  INTEL_UC_FIRMWARE_NOT_SUPPORTED);
>  }
>  
> -static void __force_fw_fetch_failures(struct intel_uc_fw *uc_fw, int e)
> -{
> -	struct drm_i915_private *i915 = __uc_fw_to_gt(uc_fw)->i915;
> -	bool user = e == -EINVAL;
> -
> -	if (i915_inject_probe_error(i915, e)) {
> -		/* non-existing blob */
> -		uc_fw->file_selected.path = "<invalid>";
> -		uc_fw->user_overridden = user;
> -	} else if (i915_inject_probe_error(i915, e)) {
> -		/* require next major version */
> -		uc_fw->file_wanted.ver.major += 1;
> -		uc_fw->file_wanted.ver.minor = 0;
> -		uc_fw->user_overridden = user;
> -	} else if (i915_inject_probe_error(i915, e)) {
> -		/* require next minor version */
> -		uc_fw->file_wanted.ver.minor += 1;
> -		uc_fw->user_overridden = user;
> -	} else if (uc_fw->file_wanted.ver.major &&
> -		   i915_inject_probe_error(i915, e)) {
> -		/* require prev major version */
> -		uc_fw->file_wanted.ver.major -= 1;
> -		uc_fw->file_wanted.ver.minor = 0;
> -		uc_fw->user_overridden = user;
> -	} else if (uc_fw->file_wanted.ver.minor &&
> -		   i915_inject_probe_error(i915, e)) {
> -		/* require prev minor version - hey, this should work! */
> -		uc_fw->file_wanted.ver.minor -= 1;
> -		uc_fw->user_overridden = user;
> -	} else if (user && i915_inject_probe_error(i915, e)) {
> -		/* officially unsupported platform */
> -		uc_fw->file_wanted.ver.major = 0;
> -		uc_fw->file_wanted.ver.minor = 0;
> -		uc_fw->user_overridden = true;
> -	}
> -}
> -
>  static void uc_unpack_css_version(struct intel_uc_fw_ver *ver, u32 css_value)
>  {
>  	/* Get version numbers from the CSS header */
> @@ -766,7 +729,7 @@ static int guc_check_version_range(struct intel_uc_fw *uc_fw)
>  		return -EINVAL;
>  	}
>  
> -	return i915_inject_probe_error(gt->i915, -EINVAL);
> +	return 0;
>  }
>  
>  static int check_fw_header(struct intel_gt *gt,
> @@ -905,13 +868,6 @@ int intel_uc_fw_fetch(struct intel_uc_fw *uc_fw)
>  	GEM_BUG_ON(!gt->wopcm.size);
>  	GEM_BUG_ON(!intel_uc_fw_is_enabled(uc_fw));
>  
> -	err = i915_inject_probe_error(i915, -ENXIO);
> -	if (err)
> -		goto fail;
> -
> -	__force_fw_fetch_failures(uc_fw, -EINVAL);
> -	__force_fw_fetch_failures(uc_fw, -ESTALE);
> -
>  	err = try_firmware_load(uc_fw, &fw);
>  	memcpy(&file_ideal, &uc_fw->file_wanted, sizeof(file_ideal));
>  
> @@ -1088,10 +1044,6 @@ static int uc_fw_xfer(struct intel_uc_fw *uc_fw, u32 dst_offset, u32 dma_flags)
>  	u64 offset;
>  	int ret;
>  
> -	ret = i915_inject_probe_error(gt->i915, -ETIMEDOUT);
> -	if (ret)
> -		return ret;
> -
>  	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
>  
>  	/* Set the source address for the uCode */
> @@ -1155,16 +1107,11 @@ int intel_uc_fw_mark_load_failed(struct intel_uc_fw *uc_fw, int err)
>   */
>  int intel_uc_fw_upload(struct intel_uc_fw *uc_fw, u32 dst_offset, u32 dma_flags)
>  {
> -	struct intel_gt *gt = __uc_fw_to_gt(uc_fw);
>  	int err;
>  
>  	/* make sure the status was cleared the last time we reset the uc */
>  	GEM_BUG_ON(intel_uc_fw_is_loaded(uc_fw));
>  
> -	err = i915_inject_probe_error(gt->i915, -ENOEXEC);
> -	if (err)
> -		return err;
> -
>  	if (!intel_uc_fw_is_loadable(uc_fw))
>  		return -ENOEXEC;
>  
> @@ -1198,10 +1145,6 @@ static int uc_fw_rsa_data_create(struct intel_uc_fw *uc_fw)
>  	void *vaddr;
>  	int err;
>  
> -	err = i915_inject_probe_error(gt->i915, -ENXIO);
> -	if (err)
> -		return err;
> -
>  	if (!uc_fw_need_rsa_in_memory(uc_fw))
>  		return 0;
>  
> @@ -1243,6 +1186,7 @@ static int uc_fw_rsa_data_create(struct intel_uc_fw *uc_fw)
>  	i915_vma_unpin_and_release(&vma, 0);
>  	return err;
>  }
> +ALLOW_ERROR_INJECTION(uc_fw_rsa_data_create, ERRNO);
>  
>  static void uc_fw_rsa_data_destroy(struct intel_uc_fw *uc_fw)
>  {
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index c97b76771917..73ae3cf7f373 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -224,9 +224,6 @@ static int i915_driver_early_probe(struct drm_i915_private *dev_priv)
>  	struct intel_display *display = dev_priv->display;
>  	int ret = 0;
>  
> -	if (i915_inject_probe_failure(dev_priv))
> -		return -ENODEV;
> -
>  	intel_device_info_runtime_init_early(dev_priv);
>  
>  	intel_step_init(dev_priv);
> @@ -276,6 +273,7 @@ static int i915_driver_early_probe(struct drm_i915_private *dev_priv)
>  	i915_workqueues_cleanup(dev_priv);
>  	return ret;
>  }
> +ALLOW_ERROR_INJECTION(i915_driver_early_probe, ERRNO);
>  
>  /**
>   * i915_driver_late_release - cleanup the setup done in
> @@ -318,9 +316,6 @@ static int i915_driver_mmio_probe(struct drm_i915_private *dev_priv)
>  	struct intel_gt *gt;
>  	int ret, i;
>  
> -	if (i915_inject_probe_failure(dev_priv))
> -		return -ENODEV;
> -
>  	ret = intel_gmch_bridge_setup(dev_priv);
>  	if (ret < 0)
>  		return ret;
> @@ -358,6 +353,7 @@ static int i915_driver_mmio_probe(struct drm_i915_private *dev_priv)
>  
>  	return ret;
>  }
> +ALLOW_ERROR_INJECTION(i915_driver_mmio_probe, ERRNO);
>  
>  /**
>   * i915_driver_mmio_release - cleanup the setup done in i915_driver_mmio_probe()
> @@ -465,9 +461,6 @@ static int i915_driver_hw_probe(struct drm_i915_private *dev_priv)
>  	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
>  	int ret;
>  
> -	if (i915_inject_probe_failure(dev_priv))
> -		return -ENODEV;
> -
>  	if (HAS_PPGTT(dev_priv)) {
>  		if (intel_vgpu_active(dev_priv) &&
>  		    !intel_vgpu_has_full_ppgtt(dev_priv)) {
> @@ -595,6 +588,7 @@ static int i915_driver_hw_probe(struct drm_i915_private *dev_priv)
>  	i915_perf_fini(dev_priv);
>  	return ret;
>  }
> +ALLOW_ERROR_INJECTION(i915_driver_hw_probe, ERRNO);
>  
>  /**
>   * i915_driver_hw_remove - cleanup the setup done in i915_driver_hw_probe()
> diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
> index 37746dd619fd..34ed82bb1b1a 100644
> --- a/drivers/gpu/drm/i915/i915_params.c
> +++ b/drivers/gpu/drm/i915/i915_params.c
> @@ -110,11 +110,6 @@ i915_param_named_unsafe(huc_firmware_path, charp, 0400,
>  i915_param_named_unsafe(gsc_firmware_path, charp, 0400,
>  	"GSC firmware path to use instead of the default one");
>  
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
> -i915_param_named_unsafe(inject_probe_failure, uint, 0400,
> -	"Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)");
> -#endif
> -
>  #if IS_ENABLED(CONFIG_DRM_I915_GVT)
>  i915_param_named(enable_gvt, bool, 0400,
>  	"Enable support for Intel GVT-g graphics virtualization host support(default:false)");
> diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
> index 0fbcb5b6d7bf..4d9d4cd3220d 100644
> --- a/drivers/gpu/drm/i915/i915_params.h
> +++ b/drivers/gpu/drm/i915/i915_params.h
> @@ -55,7 +55,6 @@ struct drm_printer;
>  	param(bool, memtest, false, 0400) \
>  	param(int, mmio_debug, -IS_ENABLED(CONFIG_DRM_I915_DEBUG_MMIO), 0600) \
>  	param(unsigned int, reset, 3, 0600) \
> -	param(unsigned int, inject_probe_failure, 0, 0) \
>  	param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE, 0400) \
>  	param(unsigned int, request_timeout_ms, CONFIG_DRM_I915_REQUEST_TIMEOUT, CONFIG_DRM_I915_REQUEST_TIMEOUT ? 0600 : 0) \
>  	param(unsigned int, lmem_size, 0, 0400) \
> diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
> index b2e311f4791a..d966a00520f1 100644
> --- a/drivers/gpu/drm/i915/i915_pci.c
> +++ b/drivers/gpu/drm/i915/i915_pci.c
> @@ -999,11 +999,6 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  	if (err)
>  		return err;
>  
> -	if (i915_inject_probe_failure(pdev_to_i915(pdev))) {
> -		i915_pci_remove(pdev);
> -		return -ENODEV;
> -	}
> -
>  	err = i915_live_selftests(pdev);
>  	if (err) {
>  		i915_pci_remove(pdev);
> @@ -1018,6 +1013,7 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  
>  	return 0;
>  }
> +ALLOW_ERROR_INJECTION(i915_pci_probe, ERRNO);
>  
>  static void i915_pci_shutdown(struct pci_dev *pdev)
>  {
> diff --git a/drivers/gpu/drm/i915/i915_utils.c b/drivers/gpu/drm/i915/i915_utils.c
> index 89b920ccbccb..8c1aad312fd4 100644
> --- a/drivers/gpu/drm/i915/i915_utils.c
> +++ b/drivers/gpu/drm/i915/i915_utils.c
> @@ -17,37 +17,9 @@ void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint)
>  	drm_notice(&i915->drm, "CI tainted: %#x by %pS\n",
>  		   taint, __builtin_return_address(0));
>  
> -	/* Failures that occur during fault injection testing are expected */
> -	if (!i915_error_injected())
> -		__add_taint_for_CI(taint);
> +	__add_taint_for_CI(taint);
>  }
>  
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
> -static unsigned int i915_probe_fail_count;
> -
> -int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
> -			      const char *func, int line)
> -{
> -	if (i915_probe_fail_count >= i915_modparams.inject_probe_failure)
> -		return 0;
> -
> -	if (++i915_probe_fail_count < i915_modparams.inject_probe_failure)
> -		return 0;
> -
> -	drm_info(&i915->drm, "Injecting failure %d at checkpoint %u [%s:%d]\n",
> -		 err, i915_modparams.inject_probe_failure, func, line);
> -
> -	i915_modparams.inject_probe_failure = 0;
> -	return err;
> -}
> -
> -bool i915_error_injected(void)
> -{
> -	return i915_probe_fail_count && !i915_modparams.inject_probe_failure;
> -}
> -
> -#endif
> -
>  bool i915_vtd_active(struct drm_i915_private *i915)
>  {
>  	if (device_iommu_mapped(i915->drm.dev))
> diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
> index 4f75115b87d6..9e5b7fcadbe2 100644
> --- a/drivers/gpu/drm/i915/i915_utils.h
> +++ b/drivers/gpu/drm/i915/i915_utils.h
> @@ -43,28 +43,8 @@ struct drm_i915_private;
>  			     __stringify(x), (long)(x))
>  #endif
>  
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
> -
> -int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
> -			      const char *func, int line);
> -#define i915_inject_probe_error(_i915, _err) \
> -	__i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
> -bool i915_error_injected(void);
> -
> -#else
> -
> -#define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
> -#define i915_error_injected() false
> -
> -#endif
> -
> -#define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
> -
>  #define i915_probe_error(i915, fmt, ...) ({ \
> -	if (i915_error_injected()) \
> -		drm_dbg(&(i915)->drm, fmt, ##__VA_ARGS__); \
> -	else \
> -		drm_err(&(i915)->drm, fmt, ##__VA_ARGS__); \
> +	drm_err(&(i915)->drm, fmt, ##__VA_ARGS__); \
>  })
>  
>  #ifndef fetch_and_zero
> diff --git a/drivers/gpu/drm/i915/intel_gvt.c b/drivers/gpu/drm/i915/intel_gvt.c
> index c3efc3454ec2..5f615ec0e580 100644
> --- a/drivers/gpu/drm/i915/intel_gvt.c
> +++ b/drivers/gpu/drm/i915/intel_gvt.c
> @@ -238,9 +238,6 @@ EXPORT_SYMBOL_NS_GPL(intel_gvt_clear_ops, "I915_GVT");
>   */
>  int intel_gvt_init(struct drm_i915_private *dev_priv)
>  {
> -	if (i915_inject_probe_failure(dev_priv))
> -		return -ENODEV;
> -
>  	mutex_lock(&intel_gvt_mutex);
>  	list_add_tail(&dev_priv->vgpu.entry, &intel_gvt_devices);
>  	if (intel_gvt_ops)
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index 4adeb271fcbf..fdd2a940f983 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -2072,9 +2072,6 @@ static int __fw_domain_init(struct intel_uncore *uncore,
>  	GEM_BUG_ON(domain_id >= FW_DOMAIN_ID_COUNT);
>  	GEM_BUG_ON(uncore->fw_domain[domain_id]);
>  
> -	if (i915_inject_probe_failure(uncore->i915))
> -		return -ENOMEM;
> -
>  	d = kzalloc(sizeof(*d), GFP_KERNEL);
>  	if (!d)
>  		return -ENOMEM;
> @@ -2118,6 +2115,7 @@ static int __fw_domain_init(struct intel_uncore *uncore,
>  
>  	return 0;
>  }
> +ALLOW_ERROR_INJECTION(__fw_domain_init, ERRNO);
>  
>  static void fw_domain_fini(struct intel_uncore *uncore,
>  			   enum forcewake_domain_id domain_id)

-- 
Jani Nikula, Intel