[PATCH] dma: gpi: remove spurious unlock in gpi_ch_init

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

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 funcion
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@linaro.org>
---
 drivers/dma/qcom/gpi.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c
index 59a36cbf9b5f..932628b319c8 100644
--- a/drivers/dma/qcom/gpi.c
+++ b/drivers/dma/qcom/gpi.c
@@ -1966,7 +1966,6 @@ 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;
 }
 
-- 
2.39.2