drm/i915/uc: Use -EIO code for GuC initialization failures

Since commit 6ca9a2beb54a ("drm/i915: Unwind i915_gem_init() failure")
we believed that we correctly handle all errors encountered during
GuC initialization, including special one that indicates request to
run driver with disabled GPU submission (-EIO).

Unfortunately since commit 121981fafe69 ("drm/i915/guc: Combine
enable_guc_loading|submission modparams") we stopped using that
error code to avoid unwanted fallback to execlist submission mode.

In result any GuC initialization failure was treated as non-recoverable
error leading to driver load abort, so we could not even read related
GuC error log to investigate cause of the problem.

For now always return -EIO on any uC hardware related failure.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190811195132.9660-5-michal.wajdeczko@intel.com

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
index a3a5918c67824c4121090321cf9ed1a762f0655b..22fa88a7c661dfc4dda7ef7374d5d9787b4c4286 100644 (file)
--- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
@@ -530,15 +530,10 @@ int intel_uc_init_hw(struct intel_uc *uc)
 err_out:
        __uc_sanitize(uc);
 
-       /*
-        * Note that there is no fallback as either user explicitly asked for
-        * the GuC or driver default option was to run with the GuC enabled.
-        */
-       if (GEM_WARN_ON(ret == -EIO))
-               ret = -EINVAL;
-
        i915_probe_error(i915, "GuC initialization failed %d\n", ret);
-       return ret;
+
+       /* We want to keep KMS alive */
+       return -EIO;
 }
 
 void intel_uc_fini_hw(struct intel_uc *uc)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6ff01a404346a16328308edfb766afc532e613ed..4752a3bf963611e45a180d927f77ae85fabfc1e7 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1463,8 +1463,10 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
        intel_init_gt_powersave(dev_priv);
 
        ret = intel_uc_init(&dev_priv->gt.uc);
-       if (ret)
+       if (ret) {
+               GEM_BUG_ON(ret == -EIO);
                goto err_pm;
+       }
 
        ret = i915_gem_init_hw(dev_priv);
        if (ret)
@@ -1526,7 +1528,8 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 err_init_hw:
        intel_uc_fini_hw(&dev_priv->gt.uc);
 err_uc_init:
-       intel_uc_fini(&dev_priv->gt.uc);
+       if (ret != -EIO)
+               intel_uc_fini(&dev_priv->gt.uc);
 err_pm:
        if (ret != -EIO) {
                intel_cleanup_gt_powersave(dev_priv);
@@ -1542,9 +1545,8 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
        intel_uncore_forcewake_put(&dev_priv->uncore, FORCEWAKE_ALL);
        mutex_unlock(&dev_priv->drm.struct_mutex);
 
-       intel_uc_cleanup_firmwares(&dev_priv->gt.uc);
-
        if (ret != -EIO) {
+               intel_uc_cleanup_firmwares(&dev_priv->gt.uc);
                i915_gem_cleanup_userptr(dev_priv);
                intel_timelines_fini(dev_priv);
        }
@@ -1553,8 +1555,8 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
                mutex_lock(&dev_priv->drm.struct_mutex);
 
                /*
-                * Allow engine initialisation to fail by marking the GPU as
-                * wedged. But we only want to do this where the GPU is angry,
+                * Allow engines or uC initialisation to fail by marking the GPU
+                * as wedged. But we only want to do this when the GPU is angry,
                 * for all other failure, such as an allocation failure, bail.
                 */
                if (!intel_gt_is_wedged(&dev_priv->gt)) {