[PATCH] drm/msm/gpu: Push gpu lock down past runpm
From: Rob Clark
Date: Thu Aug 10 2023 - 17:32:20 EST
From: Rob Clark <robdclark@xxxxxxxxxxxx>
Avoid holding gpu lock when calling runpm, to avoid this lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
6.4.3-debug+ #14 Not tainted
------------------------------------------------------
ring0/373 is trying to acquire lock:
ffffffead86efb98 (prepare_lock){+.+.}-{3:3}, at: clk_prepare_lock+0x70/0x98
but task is already holding lock:
ffffff809cd19170 (&gpu->lock){+.+.}-{3:3}, at: msm_job_run+0x7c/0x128 [msm]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&gpu->lock){+.+.}-{3:3}:
__mutex_lock+0xc8/0x388
mutex_lock_nested+0x2c/0x38
msm_job_run+0x7c/0x128 [msm]
drm_sched_main+0x264/0x354 [gpu_sched]
kthread+0xf0/0x100
ret_from_fork+0x10/0x20
-> #3 (dma_fence_map){++++}-{0:0}:
__dma_fence_might_wait+0x74/0xc0
dma_resv_lockdep+0x1f0/0x2e8
do_one_initcall+0xb4/0x214
kernel_init_freeable+0x338/0x33c
kernel_init+0x30/0x134
ret_from_fork+0x10/0x20
-> #2 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}:
fs_reclaim_acquire+0x7c/0x9c
slab_pre_alloc_hook.constprop.0+0x40/0x250
__kmem_cache_alloc_node+0x60/0x18c
kmalloc_node_trace+0x40/0x84
alloc_worker+0x2c/0x64
init_rescuer+0x34/0xe0
workqueue_init+0x168/0x1fc
kernel_init_freeable+0x15c/0x33c
kernel_init+0x30/0x134
ret_from_fork+0x10/0x20
-> #1 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire+0x3c/0x48
fs_reclaim_acquire+0x50/0x9c
slab_pre_alloc_hook.constprop.0+0x40/0x250
__kmem_cache_alloc_node+0x60/0x18c
kmalloc_trace+0x44/0x88
clk_rcg2_dfs_determine_rate+0x60/0x214
clk_core_determine_round_nolock+0xb8/0xf0
clk_core_round_rate_nolock+0x84/0x118
clk_core_round_rate_nolock+0xd8/0x118
clk_round_rate+0x6c/0xd0
geni_se_clk_tbl_get+0x78/0xc0
geni_se_clk_freq_match+0x44/0xe4
get_spi_clk_cfg+0x50/0xf4
geni_spi_set_clock_and_bw+0x54/0x104
spi_geni_prepare_message+0x130/0x174
__spi_pump_transfer_message+0x200/0x4d8
__spi_sync+0x13c/0x23c
spi_sync_locked+0x18/0x24
do_cros_ec_pkt_xfer_spi+0x124/0x3f0
cros_ec_xfer_high_pri_work+0x28/0x3c
kthread_worker_fn+0x14c/0x27c
kthread+0xf0/0x100
ret_from_fork+0x10/0x20
-> #0 (prepare_lock){+.+.}-{3:3}:
__lock_acquire+0xdf8/0x109c
lock_acquire+0x234/0x284
__mutex_lock+0xc8/0x388
mutex_lock_nested+0x2c/0x38
clk_prepare_lock+0x70/0x98
clk_prepare+0x24/0x50
clk_bulk_prepare+0x50/0x9c
a6xx_gmu_resume+0x94/0x800 [msm]
a6xx_gmu_pm_resume+0x38/0x158 [msm]
adreno_runtime_resume+0x2c/0x38 [msm]
pm_generic_runtime_resume+0x30/0x44
__rpm_callback+0x4c/0x134
rpm_callback+0x78/0x7c
rpm_resume+0x3a4/0x46c
__pm_runtime_resume+0x78/0xbc
pm_runtime_get_sync.isra.0+0x14/0x20 [msm]
msm_gpu_submit+0x4c/0x12c [msm]
msm_job_run+0x88/0x128 [msm]
drm_sched_main+0x264/0x354 [gpu_sched]
kthread+0xf0/0x100
ret_from_fork+0x10/0x20
other info that might help us debug this:
Chain exists of:
prepare_lock --> dma_fence_map --> &gpu->lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&gpu->lock);
lock(dma_fence_map);
lock(&gpu->lock);
lock(prepare_lock);
*** DEADLOCK ***
2 locks held by ring0/373:
#0: ffffffead875ae50 (dma_fence_map){++++}-{0:0}, at: drm_sched_main+0x54/0x354 [gpu_sched]
#1: ffffff809cd19170 (&gpu->lock){+.+.}-{3:3}, at: msm_job_run+0x7c/0x128 [msm]
stack backtrace:
CPU: 2 PID: 373 Comm: ring0 Not tainted 6.4.3-debug+ #14
Hardware name: Google Villager (rev1+) with LTE (DT)
Call trace:
dump_backtrace+0xb4/0xf0
show_stack+0x20/0x30
dump_stack_lvl+0x60/0x84
dump_stack+0x18/0x24
print_circular_bug+0x1cc/0x234
check_noncircular+0x78/0xac
__lock_acquire+0xdf8/0x109c
lock_acquire+0x234/0x284
__mutex_lock+0xc8/0x388
mutex_lock_nested+0x2c/0x38
clk_prepare_lock+0x70/0x98
clk_prepare+0x24/0x50
clk_bulk_prepare+0x50/0x9c
a6xx_gmu_resume+0x94/0x800 [msm]
a6xx_gmu_pm_resume+0x38/0x158 [msm]
adreno_runtime_resume+0x2c/0x38 [msm]
pm_generic_runtime_resume+0x30/0x44
__rpm_callback+0x4c/0x134
rpm_callback+0x78/0x7c
rpm_resume+0x3a4/0x46c
__pm_runtime_resume+0x78/0xbc
pm_runtime_get_sync.isra.0+0x14/0x20 [msm]
msm_gpu_submit+0x4c/0x12c [msm]
msm_job_run+0x88/0x128 [msm]
drm_sched_main+0x264/0x354 [gpu_sched]
kthread+0xf0/0x100
ret_from_fork+0x10/0x20
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_gpu.c | 11 ++++++-----
drivers/gpu/drm/msm/msm_ringbuffer.c | 7 ++-----
2 files changed, 8 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 243f988c65b7..0a5e28410e68 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -749,13 +749,11 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
struct msm_ringbuffer *ring = submit->ring;
unsigned long flags;
- WARN_ON(!mutex_is_locked(&gpu->lock));
-
pm_runtime_get_sync(&gpu->pdev->dev);
- msm_gpu_hw_init(gpu);
+ mutex_lock(&gpu->lock);
- submit->seqno = submit->hw_fence->seqno;
+ msm_gpu_hw_init(gpu);
update_sw_cntrs(gpu);
@@ -781,8 +779,11 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
gpu->funcs->submit(gpu, submit);
gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
- pm_runtime_put(&gpu->pdev->dev);
hangcheck_timer_reset(gpu);
+
+ mutex_unlock(&gpu->lock);
+
+ pm_runtime_put(&gpu->pdev->dev);
}
/*
diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c
index cb9cf41bcb9b..9d6e2e10d25a 100644
--- a/drivers/gpu/drm/msm/msm_ringbuffer.c
+++ b/drivers/gpu/drm/msm/msm_ringbuffer.c
@@ -21,6 +21,8 @@ static struct dma_fence *msm_job_run(struct drm_sched_job *job)
msm_fence_init(submit->hw_fence, fctx);
+ submit->seqno = submit->hw_fence->seqno;
+
mutex_lock(&priv->lru.lock);
for (i = 0; i < submit->nr_bos; i++) {
@@ -32,13 +34,8 @@ static struct dma_fence *msm_job_run(struct drm_sched_job *job)
mutex_unlock(&priv->lru.lock);
- /* TODO move submit path over to using a per-ring lock.. */
- mutex_lock(&gpu->lock);
-
msm_gpu_submit(gpu, submit);
- mutex_unlock(&gpu->lock);
-
return dma_fence_get(submit->hw_fence);
}
--
2.41.0