This is a note to let you know that I've just added the patch titled
Revert "drm/tidss: Annotate dma-fence critical section in commit path"
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
revert-drm-tidss-annotate-dma-fence-critical-section.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ee73b0d6f2fe119874232b3b3173de72e3bbe7e4
Author: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
Date: Wed Sep 20 15:57:16 2023 +0300
Revert "drm/tidss: Annotate dma-fence critical section in commit path"
[ Upstream commit ca34d816558c3e4c3f8fe037b5a6b16c944693de ]
This reverts commit 4d56a4f08391857ba93465de489707b66adad114.
The DMA-fence annotations cause a lockdep warning (see below). As per
https://patchwork.freedesktop.org/patch/462170/ it sounds like the
annotations don't work correctly.
======================================================
WARNING: possible circular locking dependency detected
6.6.0-rc2+ #1 Not tainted
------------------------------------------------------
kmstest/733 is trying to acquire lock:
ffff8000819377f0 (fs_reclaim){+.+.}-{0:0}, at: __kmem_cache_alloc_node+0x58/0x2d4
but task is already holding lock:
ffff800081a06aa0 (dma_fence_map){++++}-{0:0}, at: tidss_atomic_commit_tail+0x20/0xc0 [tidss]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (dma_fence_map){++++}-{0:0}:
__dma_fence_might_wait+0x5c/0xd0
dma_resv_lockdep+0x1a4/0x32c
do_one_initcall+0x84/0x2fc
kernel_init_freeable+0x28c/0x4c4
kernel_init+0x24/0x1dc
ret_from_fork+0x10/0x20
-> #1 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}:
fs_reclaim_acquire+0x70/0xe4
__kmem_cache_alloc_node+0x58/0x2d4
kmalloc_trace+0x38/0x78
__kthread_create_worker+0x3c/0x150
kthread_create_worker+0x64/0x8c
workqueue_init+0x1e8/0x2f0
kernel_init_freeable+0x11c/0x4c4
kernel_init+0x24/0x1dc
ret_from_fork+0x10/0x20
-> #0 (fs_reclaim){+.+.}-{0:0}:
__lock_acquire+0x1370/0x20d8
lock_acquire+0x1e8/0x308
fs_reclaim_acquire+0xd0/0xe4
__kmem_cache_alloc_node+0x58/0x2d4
__kmalloc_node_track_caller+0x58/0xf0
kmemdup+0x34/0x60
regmap_bulk_write+0x64/0x2c0
tc358768_bridge_pre_enable+0x8c/0x12d0 [tc358768]
drm_atomic_bridge_call_pre_enable+0x68/0x80 [drm]
drm_atomic_bridge_chain_pre_enable+0x50/0x158 [drm]
drm_atomic_helper_commit_modeset_enables+0x164/0x264 [drm_kms_helper]
tidss_atomic_commit_tail+0x58/0xc0 [tidss]
commit_tail+0xa0/0x188 [drm_kms_helper]
drm_atomic_helper_commit+0x1a8/0x1c0 [drm_kms_helper]
drm_atomic_commit+0xa8/0xe0 [drm]
drm_mode_atomic_ioctl+0x9ec/0xc80 [drm]
drm_ioctl_kernel+0xc4/0x170 [drm]
drm_ioctl+0x234/0x4b0 [drm]
drm_compat_ioctl+0x110/0x12c [drm]
__arm64_compat_sys_ioctl+0x128/0x150
invoke_syscall+0x48/0x110
el0_svc_common.constprop.0+0x40/0xe0
do_el0_svc_compat+0x1c/0x38
el0_svc_compat+0x48/0xb4
el0t_32_sync_handler+0xb0/0x138
el0t_32_sync+0x194/0x198
other info that might help us debug this:
Chain exists of:
fs_reclaim --> mmu_notifier_invalidate_range_start --> dma_fence_map
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(dma_fence_map);
lock(mmu_notifier_invalidate_range_start);
lock(dma_fence_map);
lock(fs_reclaim);
*** DEADLOCK ***
3 locks held by kmstest/733:
#0: ffff800082e5bba0 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_mode_atomic_ioctl+0x118/0xc80 [drm]
#1: ffff000004224c88 (crtc_ww_class_mutex){+.+.}-{3:3}, at: modeset_lock+0xdc/0x1a0 [drm]
#2: ffff800081a06aa0 (dma_fence_map){++++}-{0:0}, at: tidss_atomic_commit_tail+0x20/0xc0 [tidss]
stack backtrace:
CPU: 0 PID: 733 Comm: kmstest Not tainted 6.6.0-rc2+ #1
Hardware name: Toradex Verdin AM62 on Verdin Development Board (DT)
Call trace:
dump_backtrace+0x98/0x118
show_stack+0x18/0x24
dump_stack_lvl+0x60/0xac
dump_stack+0x18/0x24
print_circular_bug+0x288/0x368
check_noncircular+0x168/0x17c
__lock_acquire+0x1370/0x20d8
lock_acquire+0x1e8/0x308
fs_reclaim_acquire+0xd0/0xe4
__kmem_cache_alloc_node+0x58/0x2d4
__kmalloc_node_track_caller+0x58/0xf0
kmemdup+0x34/0x60
regmap_bulk_write+0x64/0x2c0
tc358768_bridge_pre_enable+0x8c/0x12d0 [tc358768]
drm_atomic_bridge_call_pre_enable+0x68/0x80 [drm]
drm_atomic_bridge_chain_pre_enable+0x50/0x158 [drm]
drm_atomic_helper_commit_modeset_enables+0x164/0x264 [drm_kms_helper]
tidss_atomic_commit_tail+0x58/0xc0 [tidss]
commit_tail+0xa0/0x188 [drm_kms_helper]
drm_atomic_helper_commit+0x1a8/0x1c0 [drm_kms_helper]
drm_atomic_commit+0xa8/0xe0 [drm]
drm_mode_atomic_ioctl+0x9ec/0xc80 [drm]
drm_ioctl_kernel+0xc4/0x170 [drm]
drm_ioctl+0x234/0x4b0 [drm]
drm_compat_ioctl+0x110/0x12c [drm]
__arm64_compat_sys_ioctl+0x128/0x150
invoke_syscall+0x48/0x110
el0_svc_common.constprop.0+0x40/0xe0
do_el0_svc_compat+0x1c/0x38
el0_svc_compat+0x48/0xb4
el0t_32_sync_handler+0xb0/0x138
el0t_32_sync+0x194/0x198
Fixes: 4d56a4f08391 ("drm/tidss: Annotate dma-fence critical section in commit path")
Reviewed-by: Aradhya Bhatia <a-bhatia1@xxxxxx>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920-dma-fence-annotation-revert-v1-1-7ebf6f7f5bf6@xxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/tidss/tidss_kms.c b/drivers/gpu/drm/tidss/tidss_kms.c
index c979ad1af236..d096d8d2bc8f 100644
--- a/drivers/gpu/drm/tidss/tidss_kms.c
+++ b/drivers/gpu/drm/tidss/tidss_kms.c
@@ -4,8 +4,6 @@
* Author: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
*/
-#include <linux/dma-fence.h>
-
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
@@ -25,7 +23,6 @@ static void tidss_atomic_commit_tail(struct drm_atomic_state *old_state)
{
struct drm_device *ddev = old_state->dev;
struct tidss_device *tidss = to_tidss(ddev);
- bool fence_cookie = dma_fence_begin_signalling();
dev_dbg(ddev->dev, "%s\n", __func__);
@@ -36,7 +33,6 @@ static void tidss_atomic_commit_tail(struct drm_atomic_state *old_state)
drm_atomic_helper_commit_modeset_enables(ddev, old_state);
drm_atomic_helper_commit_hw_done(old_state);
- dma_fence_end_signalling(fence_cookie);
drm_atomic_helper_wait_for_flip_done(ddev, old_state);
drm_atomic_helper_cleanup_planes(ddev, old_state);
