Re: [PATCH] gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully

[Kent Gibson]

On Wed, Sep 21, 2022 at 11:52:31AM +0800, Kent Gibson wrote:
> On Wed, Sep 21, 2022 at 11:20:20AM +0800, Meng Li wrote:
> > When running gpio test on nxp-ls1028 platform with below command
> > gpiomon --num-events=3 --rising-edge gpiochip1 25
> > There will be a warning trace as below:
> > Call trace:
> > free_irq+0x204/0x360
> > lineevent_free+0x64/0x70
> > gpio_ioctl+0x598/0x6a0
> > __arm64_sys_ioctl+0xb4/0x100
> > invoke_syscall+0x5c/0x130
> > ......
> > el0t_64_sync+0x1a0/0x1a4
> > The reason of this issue is that calling request_threaded_irq()
> > function failed, and then lineevent_free() is invoked to release
> > the resource. Since the lineevent_state::irq was already set, so
> > the subsequent invocation of free_irq() would trigger the above
> > warning call trace. To fix this issue, set the lineevent_state::irq
> > after the IRQ register successfully.
> > 
> > Fixes: 468242724143 ("gpiolib: cdev: refactor lineevent cleanup into lineevent_free")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Meng Li <Meng.Li@xxxxxxxxxxxxx>
> 
> Good pick up - the IRQ shouldn't be freed if it hasn't been successfully requested.
> 
> Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx>
> 

Oops, that should be

Reviewed-by: Kent Gibson <warthog618@xxxxxxxxx>