drm/i915: do not clean GT table on error path

The only task of intel_gt_release_all is to zero gt table. Calling
it on error path prevents intel_gt_driver_late_release_all (called from
i915_driver_late_release) to cleanup GTs, causing leakage.
After i915_driver_late_release GT array is not used anymore so
it does not need cleaning at all.

Sample leak report:

BUG i915_request (...): Objects remaining in i915_request on __kmem_cache_shutdown()
...
Object 0xffff888113420040 @offset=64
Allocated in __i915_request_create+0x75/0x610 [i915] age=18339 cpu=1 pid=1454
 kmem_cache_alloc+0x25b/0x270
 __i915_request_create+0x75/0x610 [i915]
 i915_request_create+0x109/0x290 [i915]
 __engines_record_defaults+0xca/0x440 [i915]
 intel_gt_init+0x275/0x430 [i915]
 i915_gem_init+0x135/0x2c0 [i915]
 i915_driver_probe+0x8d1/0xdc0 [i915]

v2: removed whole intel_gt_release_all

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8489
Fixes: bec68cc9 ("drm/i915: Prepare for multiple GTs")
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231115-dont_clean_gt_on_error_path-v2-1-54250125470a@intel.com

drivers/gpu/drm/i915/gt/intel_gt.c

@@ -982,8 +982,6 @@ int intel_gt_probe_all(struct drm_i915_private *i915)
 
 err:
 	i915_probe_error(i915, "Failed to initialize %s! (%d)\n", gtdef->name, ret);
-	intel_gt_release_all(i915);
-
 	return ret;
 }
 
@@ -1002,15 +1000,6 @@ int intel_gt_tiles_init(struct drm_i915_private *i915)
 	return 0;
 }
 
-void intel_gt_release_all(struct drm_i915_private *i915)
-{
-	struct intel_gt *gt;
-	unsigned int id;
-
-	for_each_gt(gt, i915, id)
-		i915->gt[id] = NULL;
-}
-
 void intel_gt_info_print(const struct intel_gt_info *info,
 			 struct drm_printer *p)
 {

drivers/gpu/drm/i915/i915_driver.c

@@ -782,7 +782,7 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	ret = i915_driver_mmio_probe(i915);
 	if (ret < 0)
-		goto out_tiles_cleanup;
+		goto out_runtime_pm_put;
 
 	ret = i915_driver_hw_probe(i915);
 	if (ret < 0)
@@ -842,8 +842,6 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	i915_ggtt_driver_late_release(i915);
 out_cleanup_mmio:
 	i915_driver_mmio_release(i915);
-out_tiles_cleanup:
-	intel_gt_release_all(i915);
 out_runtime_pm_put:
 	enable_rpm_wakeref_asserts(&i915->runtime_pm);
 	i915_driver_late_release(i915);