On Thu, 23 Jul 2020, Andy Shevchenko wrote:
> 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 <[email protected]>
> ---
> drivers/mfd/dln2.c | 4 ++++
> 1 file changed, 4 insertions(+)
Applied, thanks.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
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