[PATCH] drm/msm/a6xx: Push down GMU lock
From: Rob Clark
Date: Thu Aug 10 2023 - 16:21:28 EST
From: Rob Clark <robdclark@xxxxxxxxxxxx>
Fix another lockdep splat by pushing the GMU lock further down in the
pm_resume path, so that we aren't holding it while preparing/enabling
clks. Fixes:
======================================================
WARNING: possible circular locking dependency detected
------------------------------------------------------
6.4.3-debug+ #14 Not tainted
ffffffe487cefb98 (prepare_lock){+.+.}-{3:3}, at: clk_prepare_lock+0x70/0x98
ring0/408 is trying to acquire lock:
already holding lock:
ffffff809600c6c0 (&a6xx_gpu->gmu.lock){+.+.}-{3:3}, at: a6xx_gmu_pm_resume+0x40/0x170 [msm]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&a6xx_gpu->gmu.lock){+.+.}-{3:3}:
mutex_lock_nested+0x2c/0x38
__mutex_lock+0xc8/0x388
msm_devfreq_target+0x170/0x18c [msm]
a6xx_gpu_set_freq+0x38/0x64 [msm]
devfreq_update_target+0xb4/0xf0
devfreq_set_target+0x90/0x1e4
devfreq_monitor+0x3c/0x10c
update_devfreq+0x1c/0x28
worker_thread+0x1f0/0x260
process_one_work+0x288/0x3d8
ret_from_fork+0x10/0x20
kthread+0xf0/0x100
-> #3 (&df->lock){+.+.}-{3:3}:
mutex_lock_nested+0x2c/0x38
__mutex_lock+0xc8/0x388
devfreq_simple_ondemand_func+0x5c/0x128
msm_devfreq_get_dev_status+0x4c/0x104 [msm]
update_devfreq+0x1c/0x28
devfreq_update_target+0x68/0xf0
process_one_work+0x288/0x3d8
devfreq_monitor+0x3c/0x10c
kthread+0xf0/0x100
worker_thread+0x1f0/0x260
ret_from_fork+0x10/0x20
devfreq_add_device+0x1b4/0x564
-> #2 (&devfreq->lock){+.+.}-{3:3}:
msm_devfreq_init+0xa8/0x16c [msm]
devm_devfreq_add_device+0x6c/0xb8
adreno_gpu_init+0x248/0x2b0 [msm]
msm_gpu_init+0x368/0x54c [msm]
adreno_bind+0x264/0x2bc [msm]
a6xx_gpu_init+0x2d0/0x384 [msm]
msm_drm_bind+0x2d0/0x5f4 [msm]
component_bind_all+0x124/0x1f4
__component_add+0xd4/0x128
try_to_bring_up_aggregate_device+0x88/0x1a4
dp_display_probe+0x37c/0x3c0 [msm]
component_add+0x1c/0x28
really_probe+0x148/0x280
platform_probe+0x70/0xc0
driver_probe_device+0x44/0x100
__driver_probe_device+0xfc/0x114
bus_for_each_drv+0xb0/0xd8
__device_attach_driver+0x64/0xdc
device_initial_probe+0x1c/0x28
__device_attach+0xe4/0x140
deferred_probe_work_func+0xb0/0xc8
bus_probe_device+0x44/0xb0
worker_thread+0x1f0/0x260
process_one_work+0x288/0x3d8
ret_from_fork+0x10/0x20
kthread+0xf0/0x100
-> #1 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire+0x50/0x9c
__fs_reclaim_acquire+0x3c/0x48
__kmem_cache_alloc_node+0x60/0x18c
slab_pre_alloc_hook.constprop.0+0x40/0x250
clk_rcg2_dfs_determine_rate+0x60/0x214
kmalloc_trace+0x44/0x88
clk_core_round_rate_nolock+0x84/0x118
clk_core_determine_round_nolock+0xb8/0xf0
clk_round_rate+0x6c/0xd0
clk_core_round_rate_nolock+0xd8/0x118
geni_se_clk_freq_match+0x44/0xe4
geni_se_clk_tbl_get+0x78/0xc0
geni_spi_set_clock_and_bw+0x54/0x104
get_spi_clk_cfg+0x50/0xf4
__spi_pump_transfer_message+0x200/0x4d8
spi_geni_prepare_message+0x130/0x174
spi_sync_locked+0x18/0x24
__spi_sync+0x13c/0x23c
cros_ec_xfer_high_pri_work+0x28/0x3c
do_cros_ec_pkt_xfer_spi+0x124/0x3f0
kthread+0xf0/0x100
kthread_worker_fn+0x14c/0x27c
ret_from_fork+0x10/0x20
__lock_acquire+0xdf8/0x109c
-> #0 (prepare_lock){+.+.}-{3:3}:
__mutex_lock+0xc8/0x388
lock_acquire+0x234/0x284
clk_prepare_lock+0x70/0x98
mutex_lock_nested+0x2c/0x38
clk_bulk_prepare+0x50/0x9c
clk_prepare+0x24/0x50
a6xx_gmu_pm_resume+0x48/0x170 [msm]
a6xx_gmu_resume+0x94/0x7d8 [msm]
pm_generic_runtime_resume+0x30/0x44
adreno_runtime_resume+0x2c/0x38 [msm]
rpm_callback+0x78/0x7c
__rpm_callback+0x4c/0x134
__pm_runtime_resume+0x78/0xbc
rpm_resume+0x3a4/0x46c
msm_gpu_submit+0x4c/0x12c [msm]
pm_runtime_get_sync.isra.0+0x14/0x20 [msm]
drm_sched_main+0x264/0x354 [gpu_sched]
msm_job_run+0x88/0x128 [msm]
ret_from_fork+0x10/0x20
kthread+0xf0/0x100
other info that might help us debug this:
Chain exists of:
prepare_lock --> &df->lock --> &a6xx_gpu->gmu.lock
Possible unsafe locking scenario:
---- ----
CPU0 CPU1
lock(&df->lock);
lock(&a6xx_gpu->gmu.lock);
lock(prepare_lock);
lock(&a6xx_gpu->gmu.lock);
*** DEADLOCK ***
3 locks held by ring0/408:
#1: ffffff809600c170 (&gpu->lock){+.+.}-{3:3}, at: msm_job_run+0x7c/0x128 [msm]
#0: ffffffe487d5ae50 (dma_fence_map){++++}-{0:0}, at: drm_sched_main+0x54/0x354 [gpu_sched]
#2: ffffff809600c6c0 (&a6xx_gpu->gmu.lock){+.+.}-{3:3}, at: a6xx_gmu_pm_resume+0x40/0x170 [msm]
CPU: 1 PID: 408 Comm: ring0 Not tainted 6.4.3-debug+ #14
stack backtrace:
Call trace:
Hardware name: Google Villager (rev1+) with LTE (DT)
show_stack+0x20/0x30
dump_backtrace+0xb4/0xf0
dump_stack+0x18/0x24
dump_stack_lvl+0x60/0x84
check_noncircular+0x78/0xac
print_circular_bug+0x1cc/0x234
lock_acquire+0x234/0x284
__lock_acquire+0xdf8/0x109c
mutex_lock_nested+0x2c/0x38
__mutex_lock+0xc8/0x388
clk_prepare+0x24/0x50
clk_prepare_lock+0x70/0x98
a6xx_gmu_resume+0x94/0x7d8 [msm]
clk_bulk_prepare+0x50/0x9c
adreno_runtime_resume+0x2c/0x38 [msm]
a6xx_gmu_pm_resume+0x48/0x170 [msm]
__rpm_callback+0x4c/0x134
pm_generic_runtime_resume+0x30/0x44
rpm_resume+0x3a4/0x46c
rpm_callback+0x78/0x7c
pm_runtime_get_sync.isra.0+0x14/0x20 [msm]
__pm_runtime_resume+0x78/0xbc
msm_job_run+0x88/0x128 [msm]
msm_gpu_submit+0x4c/0x12c [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/adreno/a6xx_gmu.c | 4 ++++
drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 2 --
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 3e0033666a2a..5eb0e812f168 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -965,6 +965,8 @@ int a6xx_gmu_resume(struct a6xx_gpu *a6xx_gpu)
/* Set the bus quota to a reasonable value for boot */
a6xx_gmu_set_initial_bw(gpu, gmu);
+ mutex_lock(&gmu->lock);
+
/* Enable the GMU interrupt */
gmu_write(gmu, REG_A6XX_GMU_AO_HOST_INTERRUPT_CLR, ~0);
gmu_write(gmu, REG_A6XX_GMU_AO_HOST_INTERRUPT_MASK, ~A6XX_GMU_IRQ_MASK);
@@ -1009,6 +1011,8 @@ int a6xx_gmu_resume(struct a6xx_gpu *a6xx_gpu)
pm_runtime_put(gmu->dev);
}
+ mutex_unlock(&gmu->lock);
+
return ret;
}
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 67dd2eeecf62..da300dce10fa 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -1914,9 +1914,7 @@ static int a6xx_gmu_pm_resume(struct msm_gpu *gpu)
trace_msm_gpu_resume(0);
- mutex_lock(&a6xx_gpu->gmu.lock);
ret = a6xx_gmu_resume(a6xx_gpu);
- mutex_unlock(&a6xx_gpu->gmu.lock);
if (ret)
return ret;
--
2.41.0