This is a note to let you know that I've just added the patch titled
dma: gpi: remove spurious unlock in gpi_ch_init
to the 5.15-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:
dma-gpi-remove-spurious-unlock-in-gpi_ch_init.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8a7b0a8b2eb7602662c2f1e4bc772b288e6f0995
Author: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Date: Mon Apr 10 02:33:55 2023 +0300
dma: gpi: remove spurious unlock in gpi_ch_init
[ Upstream commit 91d6a468e335571f1e67e046050dea9af5fa4ebe ]
gpi_ch_init() doesn't lock the ctrl_lock mutex, so there is no need to
unlock it too. Instead the mutex is handled by the function
gpi_alloc_chan_resources(), which properly locks and unlocks the mutex.
=====================================
WARNING: bad unlock balance detected!
6.3.0-rc5-00253-g99792582ded1-dirty #15 Not tainted
-------------------------------------
kworker/u16:0/9 is trying to release lock (&gpii->ctrl_lock) at:
[<ffffb99d04e1284c>] gpi_alloc_chan_resources+0x108/0x5bc
but there are no more locks to release!
other info that might help us debug this:
6 locks held by kworker/u16:0/9:
#0: ffff575740010938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x220/0x594
#1: ffff80000809bdd0 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x220/0x594
#2: ffff575740f2a0f8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x38/0x188
#3: ffff57574b5570f8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x38/0x188
#4: ffffb99d06a2f180 (of_dma_lock){+.+.}-{3:3}, at: of_dma_request_slave_channel+0x138/0x280
#5: ffffb99d06a2ee20 (dma_list_mutex){+.+.}-{3:3}, at: dma_get_slave_channel+0x28/0x10c
stack backtrace:
CPU: 7 PID: 9 Comm: kworker/u16:0 Not tainted 6.3.0-rc5-00253-g99792582ded1-dirty #15
Hardware name: Google Pixel 3 (DT)
Workqueue: events_unbound deferred_probe_work_func
Call trace:
dump_backtrace+0xa0/0xfc
show_stack+0x18/0x24
dump_stack_lvl+0x60/0xac
dump_stack+0x18/0x24
print_unlock_imbalance_bug+0x130/0x148
lock_release+0x270/0x300
__mutex_unlock_slowpath+0x48/0x2cc
mutex_unlock+0x20/0x2c
gpi_alloc_chan_resources+0x108/0x5bc
dma_chan_get+0x84/0x188
dma_get_slave_channel+0x5c/0x10c
gpi_of_dma_xlate+0x110/0x1a0
of_dma_request_slave_channel+0x174/0x280
dma_request_chan+0x3c/0x2d4
geni_i2c_probe+0x544/0x63c
platform_probe+0x68/0xc4
really_probe+0x148/0x2ac
__driver_probe_device+0x78/0xe0
driver_probe_device+0x3c/0x160
__device_attach_driver+0xb8/0x138
bus_for_each_drv+0x84/0xe0
__device_attach+0x9c/0x188
device_initial_probe+0x14/0x20
bus_probe_device+0xac/0xb0
device_add+0x60c/0x7d8
of_device_add+0x44/0x60
of_platform_device_create_pdata+0x90/0x124
of_platform_bus_create+0x15c/0x3c8
of_platform_populate+0x58/0xf8
devm_of_platform_populate+0x58/0xbc
geni_se_probe+0xf0/0x164
platform_probe+0x68/0xc4
really_probe+0x148/0x2ac
__driver_probe_device+0x78/0xe0
driver_probe_device+0x3c/0x160
__device_attach_driver+0xb8/0x138
bus_for_each_drv+0x84/0xe0
__device_attach+0x9c/0x188
device_initial_probe+0x14/0x20
bus_probe_device+0xac/0xb0
deferred_probe_work_func+0x8c/0xc8
process_one_work+0x2bc/0x594
worker_thread+0x228/0x438
kthread+0x108/0x10c
ret_from_fork+0x10/0x20
Fixes: 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230409233355.453741-1-dmitry.baryshkov@xxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c
index 1a1b7d8458c93..1e87fe6c62af2 100644
--- a/drivers/dma/qcom/gpi.c
+++ b/drivers/dma/qcom/gpi.c
@@ -1961,7 +1961,6 @@ static int gpi_ch_init(struct gchan *gchan)
error_config_int:
gpi_free_ring(&gpii->ev_ring, gpii);
exit_gpi_init:
- mutex_unlock(&gpii->ctrl_lock);
return ret;
}
