From: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Wed, 26 Jan 2022 08:15:38 +0000 (+0200)
Subject: drm/i915: Fix oops due to missing stack depot
X-Git-Tag: v5.19~932^2~19^2~36
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=751a9d69b19702af35b0fedfb8ff362027c1cf0c;p=mirror_ubuntu-kernels.git

drm/i915: Fix oops due to missing stack depot

We call __save_depot_stack() unconditionally so the stack depot
must always be initialized or else we'll oops on platforms without
runtime pm support.

Presumably we've not seen this in CI due to stack_depot_init()
already getting called via drm_mm_init()+CONFIG_DRM_DEBUG_MM.

Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com> # stackdepot
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Fixes: 2dba5eb1c73b ("lib/stackdepot: allow optional init and stack_table allocation by kvmalloc()")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220126081539.23227-1-ville.syrjala@linux.intel.com
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Imre Deak <imre.deak@intel.com>
---

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 53f1ccb78849..64c2708efc9e 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -68,9 +68,7 @@ static noinline depot_stack_handle_t __save_depot_stack(void)
 static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
 {
 	spin_lock_init(&rpm->debug.lock);
-
-	if (rpm->available)
-		stack_depot_init();
+	stack_depot_init();
 }
 
 static noinline depot_stack_handle_t