Re: [PATCH 4/5] input/rmi4/rmi_driver: check if irq_find_mapping returns 0

[Lucas Stach <l.stach@pengutronix.de>]

Hi Hans,

On Di, 2019-11-19 at 11:51 +0100, Hans Verkuil wrote:
> The irq_find_mapping() function can return 0 when called in the
> rmi_process_interrupt_requests() function.
> 
> This causes a kernel crash. Check for a 0 value and skip calling
> handle_nested_irq() in that case.
> 
> This was tested with the F54 function enabled on a Lenovo X1 Carbon.
> 
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Fixes: 24d28e4f1271 ("Input: synaptics-rmi4 - convert irq distribution to irq_domain")

This is already fixed upstream by 549766ac2ac1
"Input: synaptics-rmi4 - clear IRQ enables for F54"

Regards,
Lucas

> ---
>  drivers/input/rmi4/rmi_driver.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
> index 772493b1f665..6085ec424a84 100644
> --- a/drivers/input/rmi4/rmi_driver.c
> +++ b/drivers/input/rmi4/rmi_driver.c
> @@ -154,8 +154,12 @@ static int rmi_process_interrupt_requests(struct rmi_device *rmi_dev)
>  	 */
>  	mutex_unlock(&data->irq_mutex);
>  
> -	for_each_set_bit(i, data->irq_status, data->irq_count)
> -		handle_nested_irq(irq_find_mapping(data->irqdomain, i));
> +	for_each_set_bit(i, data->irq_status, data->irq_count) {
> +		unsigned int irq = irq_find_mapping(data->irqdomain, i);
> +
> +		if (irq)
> +			handle_nested_irq(irq);
> +	}
>  
>  	if (data->input)
>  		input_sync(data->input);