On 20-Sep-23 18:27, Tomi Valkeinen wrote: > 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") > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> Reviewed-by: Aradhya Bhatia <a-bhatia1@xxxxxx> Regards Aradhya > --- > drivers/gpu/drm/tidss/tidss_kms.c | 4 ---- > 1 file changed, 4 deletions(-) > > 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); >
