6.6-stable review patch. If anyone has any objections, please let me know.
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From: Defa Li defa.li@mediatek.com
[ Upstream commit 6cf7b65f7029914dc0cd7db86fac9ee5159008c6 ]
A deadlock may happen since the i3c_master_register() acquires &i3cbus->lock twice. See the log below. Use i3cdev->desc->info instead of calling i3c_device_info() to avoid acquiring the lock twice.
v2: - Modified the title and commit message
============================================ WARNING: possible recursive locking detected 6.11.0-mainline -------------------------------------------- init/1 is trying to acquire lock: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_bus_normaluse_lock
but task is already holding lock: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register
other info that might help us debug this: Possible unsafe locking scenario:
CPU0 ---- lock(&i3cbus->lock); lock(&i3cbus->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by init/1: #0: fcffff809b6798f8 (&dev->mutex){....}-{3:3}, at: __driver_attach #1: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register
stack backtrace: CPU: 6 UID: 0 PID: 1 Comm: init Call trace: dump_backtrace+0xfc/0x17c show_stack+0x18/0x28 dump_stack_lvl+0x40/0xc0 dump_stack+0x18/0x24 print_deadlock_bug+0x388/0x390 __lock_acquire+0x18bc/0x32ec lock_acquire+0x134/0x2b0 down_read+0x50/0x19c i3c_bus_normaluse_lock+0x14/0x24 i3c_device_get_info+0x24/0x58 i3c_device_uevent+0x34/0xa4 dev_uevent+0x310/0x384 kobject_uevent_env+0x244/0x414 kobject_uevent+0x14/0x20 device_add+0x278/0x460 device_register+0x20/0x34 i3c_master_register_new_i3c_devs+0x78/0x154 i3c_master_register+0x6a0/0x6d4 mtk_i3c_master_probe+0x3b8/0x4d8 platform_probe+0xa0/0xe0 really_probe+0x114/0x454 __driver_probe_device+0xa0/0x15c driver_probe_device+0x3c/0x1ac __driver_attach+0xc4/0x1f0 bus_for_each_dev+0x104/0x160 driver_attach+0x24/0x34 bus_add_driver+0x14c/0x294 driver_register+0x68/0x104 __platform_driver_register+0x20/0x30 init_module+0x20/0xfe4 do_one_initcall+0x184/0x464 do_init_module+0x58/0x1ec load_module+0xefc/0x10c8 __arm64_sys_finit_module+0x238/0x33c invoke_syscall+0x58/0x10c el0_svc_common+0xa8/0xdc do_el0_svc+0x1c/0x28 el0_svc+0x50/0xac el0t_64_sync_handler+0x70/0xbc el0t_64_sync+0x1a8/0x1ac
Signed-off-by: Defa Li defa.li@mediatek.com Link: https://lore.kernel.org/r/20241107132549.25439-1-defa.li@mediatek.com Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i3c/master.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 5d737bdbfe478..b77ddec6025d7 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -280,7 +280,8 @@ static int i3c_device_uevent(const struct device *dev, struct kobj_uevent_env *e struct i3c_device_info devinfo; u16 manuf, part, ext;
- i3c_device_get_info(i3cdev, &devinfo); + if (i3cdev->desc) + devinfo = i3cdev->desc->info; manuf = I3C_PID_MANUF_ID(devinfo.pid); part = I3C_PID_PART_ID(devinfo.pid); ext = I3C_PID_EXTRA_INFO(devinfo.pid);