Subject: linux-next: build failure after merge of the drm-misc tree

From: Stephen Rothwell <[email-masked]>
Date: Fri, 15 Oct 2021 20:26:48 +1100

Hi all,

After merging the drm-misc tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

drivers/gpu/drm/drm_modeset_lock.c:111:29: error: conflicting types for '__stack_depot_save'
  111 | static depot_stack_handle_t __stack_depot_save(void)
      |                             ^~~~~~~~~~~~~~~~~~
In file included from include/linux/page_ext.h:7,
                 from include/linux/mm.h:25,
                 from include/linux/kallsyms.h:13,
                 from include/linux/bpf.h:20,
                 from include/linux/bpf-cgroup.h:5,
                 from include/linux/cgroup-defs.h:22,
                 from include/linux/cgroup.h:28,
                 from include/linux/memcontrol.h:13,
                 from include/linux/swap.h:9,
                 from include/linux/suspend.h:5,
                 from include/linux/regulator/consumer.h:35,
                 from include/linux/i2c.h:18,
                 from include/drm/drm_crtc.h:28,
                 from include/drm/drm_atomic.h:31,
                 from drivers/gpu/drm/drm_modeset_lock.c:24:
include/linux/stackdepot.h:18:22: note: previous declaration of '__stack_depot_save' was here
   18 | depot_stack_handle_t __stack_depot_save(unsigned long *entries,
      |                      ^~~~~~~~~~~~~~~~~~

Caused by commit

  cd06ab2fd48f ("drm/locking: add backtrace for locking contended locks without backoff")

This may only have been revealed because of another fix I have had to
apply today.

I have applied the following patch for today.

From: Stephen Rothwell <[email-masked]>
Date: Fri, 15 Oct 2021 20:17:52 +1100
Subject: [PATCH] drm/locking: fix for name conflict

Fixes: cd06ab2fd48f ("drm/locking: add backtrace for locking contended locks without backoff")
Signed-off-by: Stephen Rothwell <[email-masked]>
---
 drivers/gpu/drm/drm_modeset_lock.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c
index 4d32b61fa1fd..ee36dd20900d 100644
--- a/drivers/gpu/drm/drm_modeset_lock.c
+++ b/drivers/gpu/drm/drm_modeset_lock.c
@@ -79,7 +79,7 @@
 static DEFINE_WW_CLASS(crtc_ww_class);
 
 #if IS_ENABLED(CONFIG_DRM_DEBUG_MODESET_LOCK)
-static noinline depot_stack_handle_t __stack_depot_save(void)
+static noinline depot_stack_handle_t __drm_stack_depot_save(void)
 {
 	unsigned long entries[8];
 	unsigned int n;
@@ -108,7 +108,7 @@ static void __stack_depot_print(depot_stack_handle_t stack_depot)
 	kfree(buf);
 }
 #else /* CONFIG_DRM_DEBUG_MODESET_LOCK */
-static depot_stack_handle_t __stack_depot_save(void)
+static depot_stack_handle_t __drm_stack_depot_save(void)
 {
 	return 0;
 }
@@ -317,7 +317,7 @@ static inline int modeset_lock(struct drm_modeset_lock *lock,
 		ret = 0;
 	} else if (ret == -EDEADLK) {
 		ctx->contended = lock;
-		ctx->stack_depot = __stack_depot_save();
+		ctx->stack_depot = __drm_stack_depot_save();
 	}
 
 	return ret;
-- 
2.33.0

-- 
Cheers,
Stephen Rothwell