From ab7cc6a0ebc11a8c7a7f6ab834bd0d7bdc852af5 Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Mon, 10 Apr 2023 02:33:55 +0300 Subject: [PATCH] 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: [] 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 Link: https://lore.kernel.org/r/20230409233355.453741-1-dmitry.baryshkov@linaro.org Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- 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 59a36cbf9b5f7f..932628b319c812 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; }