[PATCH 6.8 631/715] mei: vsc: Call wake_up() in the threaded IRQ handler

From: Sasha Levin
Date: Sun Mar 24 2024 - 20:56:14 EST


From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>

[ Upstream commit 058a38acba15fd8e7b262ec6e17c4204cb15f984 ]

The hard IRQ handler vsc_tp_irq() is called with a raw spinlock taken.
wake_up() acquires a spinlock, a sleeping lock on PREEMPT_RT. This leads
to sleeping in atomic context.

Move the wake_up() call to the threaded IRQ handler vsc_tp_thread_isr()
where it can be safely called.

Fixes: 566f5ca97680 ("mei: Add transport driver for IVSC device")
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Tested-and-Reviewed-by: Wentong Wu <wentong.wu@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240219195807.517742-2-sakari.ailus@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/misc/mei/vsc-tp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/mei/vsc-tp.c b/drivers/misc/mei/vsc-tp.c
index 55f7db490d3bb..0e623700c3b0e 100644
--- a/drivers/misc/mei/vsc-tp.c
+++ b/drivers/misc/mei/vsc-tp.c
@@ -416,8 +416,6 @@ static irqreturn_t vsc_tp_isr(int irq, void *data)

atomic_inc(&tp->assert_cnt);

- wake_up(&tp->xfer_wait);
-
return IRQ_WAKE_THREAD;
}

@@ -425,6 +423,8 @@ static irqreturn_t vsc_tp_thread_isr(int irq, void *data)
{
struct vsc_tp *tp = data;

+ wake_up(&tp->xfer_wait);
+
if (tp->event_notify)
tp->event_notify(tp->event_notify_context);

--
2.43.0