[PATCH AUTOSEL 5.15 2/6] i3c: mipi-i3c-hci: Mask ring interrupts before ring stop request

[PATCH AUTOSEL 5.15 2/6] i3c: mipi-i3c-hci: Mask ring interrupts before ring stop request

[Sasha Levin]

From: Jarkko Nikula <jarkko.nikula@linux.intel.com>

[ Upstream commit 6ca2738174e4ee44edb2ab2d86ce74f015a0cc32 ]

Bus cleanup path in DMA mode may trigger a RING_OP_STAT interrupt when
the ring is being stopped. Depending on timing between ring stop request
completion, interrupt handler removal and code execution this may lead
to a NULL pointer dereference in hci_dma_irq_handler() if it gets to run
after the io_data pointer is set to NULL in hci_dma_cleanup().

Prevent this my masking the ring interrupts before ring stop request.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20240920144432.62370-2-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index b9b6be1864384..61a5abac50dc0 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -174,10 +174,10 @@ static void hci_dma_cleanup(struct i3c_hci *hci)
 	for (i = 0; i < rings->total; i++) {
 		rh = &rings->headers[i];
 
+		rh_reg_write(INTR_SIGNAL_ENABLE, 0);
 		rh_reg_write(RING_CONTROL, 0);
 		rh_reg_write(CR_SETUP, 0);
 		rh_reg_write(IBI_SETUP, 0);
-		rh_reg_write(INTR_SIGNAL_ENABLE, 0);
 
 		if (rh->xfer)
 			dma_free_coherent(&hci->master.dev,
-- 
2.43.0


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[PATCH AUTOSEL 5.15 6/6] i3c: Use i3cdev->desc->info instead of calling i3c_device_get_info() to avoid deadlock

[Sasha Levin]

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 b6abbb0acbbd3..c4663501a971c 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -279,7 +279,8 @@ static int i3c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 	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);
-- 
2.43.0


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