From: Andy Shevchenko andriy.shevchenko@linux.intel.com
[ Upstream commit 3d858942250820b9adc35f963a257481d6d4c81d ]
The event handler loop must be run with interrupts disabled. Otherwise we will have a warning:
[ 1970.785649] irq 31 handler lineevent_irq_handler+0x0/0x20 enabled interrupts [ 1970.792739] WARNING: CPU: 0 PID: 0 at kernel/irq/handle.c:159 __handle_irq_event_percpu+0x162/0x170 [ 1970.860732] RIP: 0010:__handle_irq_event_percpu+0x162/0x170 ... [ 1970.946994] Call Trace: [ 1970.949446] <IRQ> [ 1970.951471] handle_irq_event_percpu+0x2c/0x80 [ 1970.955921] handle_irq_event+0x23/0x43 [ 1970.959766] handle_simple_irq+0x57/0x70 [ 1970.963695] generic_handle_irq+0x42/0x50 [ 1970.967717] dln2_rx+0xc1/0x210 [dln2] [ 1970.971479] ? usb_hcd_unmap_urb_for_dma+0xa6/0x1c0 [ 1970.976362] __usb_hcd_giveback_urb+0x77/0xe0 [ 1970.980727] usb_giveback_urb_bh+0x8e/0xe0 [ 1970.984837] tasklet_action_common.isra.0+0x4a/0xe0 ...
Recently xHCI driver switched to tasklets in the commit 36dc01657b49 ("usb: host: xhci: Support running urb giveback in tasklet context").
The handle_irq_event_* functions are expected to be called with interrupts disabled and they rightfully complain here because we run in tasklet context with interrupts enabled.
Use a event spinlock to protect event handler from being interrupted.
Note, that there are only two users of this GPIO and ADC drivers and both of them are using generic_handle_irq() which makes above happen.
Fixes: 338a12814297 ("mfd: Add support for Diolan DLN-2 devices") Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Lee Jones lee.jones@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mfd/dln2.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c index 6ea0dd37b4535..fe614ba5fec90 100644 --- a/drivers/mfd/dln2.c +++ b/drivers/mfd/dln2.c @@ -290,7 +290,11 @@ static void dln2_rx(struct urb *urb) len = urb->actual_length - sizeof(struct dln2_header);
if (handle == DLN2_HANDLE_EVENT) { + unsigned long flags; + + spin_lock_irqsave(&dln2->event_cb_lock, flags); dln2_run_event_callbacks(dln2, id, echo, data, len); + spin_unlock_irqrestore(&dln2->event_cb_lock, flags); } else { /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */ if (dln2_transfer_complete(dln2, urb, handle, echo))