[PATCH] [i2c-tegra] Do not mark ACPI devices as irq safe

From: Breno Leitao
Date: Thu Jun 06 2024 - 09:27:43 EST


On ACPI machines, the tegra i2c module encounters an issue due to a
mutex being called inside a spinlock. This leads to the following bug:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1282, name: kssif0010
preempt_count: 0, expected: 0
RCU nest depth: 0, expected: 0
irq event stamp: 0

Call trace:
dump_backtrace+0xf0/0x140
show_stack (./arch/x86/include/asm/current.h:49
arch/x86/kernel/dumpstack.c:312)
dump_stack_lvl (lib/dump_stack.c:89 lib/dump_stack.c:115)
dump_stack (lib/earlycpio.c:61)
__might_resched (./arch/x86/include/asm/current.h:49
kernel/sched/core.c:10297)
__might_sleep (./include/linux/lockdep.h:231
kernel/sched/core.c:10236)
__mutex_lock_common+0x5c/0x2190
mutex_lock_nested (kernel/locking/mutex.c:751)
acpi_subsys_runtime_resume+0xb8/0x160
__rpm_callback+0x1cc/0x4b0
rpm_resume+0xa60/0x1078
__pm_runtime_resume+0xbc/0x130
tegra_i2c_xfer+0x74/0x398
__i2c_transfer (./include/trace/events/i2c.h:122 drivers/i2c/i2c-core-base.c:2258)

The problem arises because during __pm_runtime_resume(), the spinlock
&dev->power.lock is acquired before rpm_resume() is called. Later,
rpm_resume() invokes acpi_subsys_runtime_resume(), which relies on
mutexes, triggering the error.

To address this issue, devices on ACPI are now marked as not IRQ-safe,
considering the dependency of acpi_subsys_runtime_resume() on mutexes.

Co-developed-by: Michael van der Westhuizen <rmikey@xxxxxxxx>
Signed-off-by: Michael van der Westhuizen <rmikey@xxxxxxxx>
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-tegra.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 85b31edc558d..6d783ecc3431 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -1804,7 +1804,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
* VI I2C device shouldn't be marked as IRQ-safe because VI I2C won't
* be used for atomic transfers.
*/
- if (!IS_VI(i2c_dev))
+ if (!IS_VI(i2c_dev) && !ACPI_HANDLE(i2c_dev->dev))
pm_runtime_irq_safe(i2c_dev->dev);

pm_runtime_enable(i2c_dev->dev);
--
2.43.0