Re: [PATCH] serial: 8250_fintek: fix the mismatched IRQ mode

From: Ricardo Ribalda Delgado
Date: Mon Jun 27 2016 - 06:26:15 EST


Hi Peter,. Hi Greg

On Fri, May 27, 2016 at 4:02 AM, Ji-Ze Hong (Peter Hong)
<hpeter@xxxxxxxxx> wrote:
> {
> struct fintek_8250 *pdata;
> struct fintek_8250 probe_data;
> + struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
> + bool level_mode = irqd_is_level_type(irq_data);

I see a potential problem with this patch:

If irq_get_irq_data fails, it will return NULL, resulting on a
segmentation fault on irqd_is_level_type:



#define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)


I believe that we need to add error checks here

>
> if (find_base_port(&probe_data, uart->port.iobase))
> return -ENODEV;
> @@ -192,5 +226,5 @@ int fintek_8250_probe(struct uart_8250_port *uart)
> uart->port.rs485_config = fintek_8250_rs485_config;
> uart->port.private_data = pdata;
>
> - return 0;
> + return fintek_8250_set_irq_mode(pdata, level_mode);

Also why do not call irq_get_irq_data() and irqd_is_level_type()
before return? There is no need to do that work if the probe
determines that it is not a fintek chip.


Greg, this is already queued for 4.7.... what shall we do here?


Regards!




--
Ricardo Ribalda