Re: [PATCH 2/7] can: m_can: m_can_rx_handler(): only handle active interrupts

["Markus Schneider-Pargmann" <msp@baylibre.com>]

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On Tue Aug 12, 2025 at 7:36 PM CEST, Marc Kleine-Budde wrote:
> Among other things, the M_CAN IP core has an Interrupt Register (IR)
> and an Interrupt Enable (IE) register. An interrupt is triggered if at
> least 1 bit is set in the bitwise and of IR and IE.
>
> Depending on the configuration not all interrupts are enabled in the
> IE register. However the m_can_rx_handler() IRQ handler looks at all
> interrupts not just the enabled ones. This may lead to handling of not
> activated interrupts.

But isn't that happening for m_can_interrupt_handler() in general then?

Best
Markus

>
> Fix the problem and mask the irqstatus (IR register) with the
> active_interrupts (cache value of IE register).
>
> Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support")
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  drivers/net/can/m_can/m_can.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index fe74dbd2c966..a51dc0bb8124 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -1006,6 +1006,7 @@ static int m_can_rx_handler(struct net_device *dev, int quota, u32 irqstatus)
>  	int rx_work_or_err;
>  	int work_done = 0;
>  
> +	irqstatus &= cdev->active_interrupts;
>  	if (!irqstatus)
>  		goto end;
>  


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