Re: [PATCH 3/3] can: flexcan: handle S32G2/S32G3 separate interrupt lines

[Marc Kleine-Budde]

On 19.11.2024 20:26:26, Vincent Mailhol wrote:
> On 19/11/2024 at 19:01, Ciprian Marian Costea wrote:
> > On 11/19/2024 11:26 AM, Vincent Mailhol wrote:
> >> On 19/11/2024 at 17:10, Ciprian Costea wrote:
> 
> (...)
> 
> >>>   +    if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SECONDARY_MB_IRQ) {
> >>> +        err = request_irq(priv->irq_secondary_mb,
> >>> +                  flexcan_irq, IRQF_SHARED, dev->name, dev);
> >>> +        if (err)
> >>> +            goto out_free_irq_err;
> >>> +    }
> >>
> >> Is the logic here correct?
> >>
> >>    request_irq(priv->irq_err, flexcan_irq, IRQF_SHARED, dev->name, dev);
> >>
> >> is called only if the device has the FLEXCAN_QUIRK_NR_IRQ_3 quirk.
> >>
> >> So, if the device has the FLEXCAN_QUIRK_SECONDARY_MB_IRQ but not the
> >> FLEXCAN_QUIRK_NR_IRQ_3, you may end up trying to free an irq which was
> >> not initialized.
> >>
> >> Did you confirm if it is safe to call free_irq() on an uninitialized irq?
> >>
> >> (and I can see that currently there is no such device with
> >> FLEXCAN_QUIRK_SECONDARY_MB_IRQ but without FLEXCAN_QUIRK_NR_IRQ_3, but
> >> who knows if such device will be introduced in the future?)
> >>
> > 
> > Hello Vincent,
> > 
> > Thanks for your review. Indeed this seems to be an incorrect logic since
> > I do not want to create any dependency between 'FLEXCAN_QUIRK_NR_IRQ_3'
> > and 'FLEXCAN_QUIRK_SECONDARY_MB_IRQ'.
> > 
> > I will change the impacted section to:
> >     if (err) {
> >         if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3)
> >             goto out_free_irq_err;
> >         else
> >             goto out_free_irq;
> >     }
> 
> This is better. Alternatively, you could move the check into the label:

+1

>   out_free_irq_err:
>   	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3)
>   		free_irq(priv->irq_err, dev);
> 
> But this is not a strong preference, I let you pick the one which you
> prefer.

regards,
Marc

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