Re: [patch 24/35] net: brcmfmac: Replace in_interrupt()

[Ulf Hansson]

On Mon, 28 Sep 2020 at 09:35, Arend Van Spriel
<arend.vanspriel@xxxxxxxxxxxx> wrote:
>
> + Uffe
>
> On 9/27/2020 9:49 PM, Thomas Gleixner wrote:
> > @@ -85,7 +85,7 @@ static void brcmf_sdiod_ib_irqhandler(st
> >
> >       brcmf_dbg(INTR, "IB intr triggered\n");
> >
> > -     brcmf_sdio_isr(sdiodev->bus);
> > +     brcmf_sdio_isr(sdiodev->bus, false);
> >   }
>
> Hi Uffe,
>
> I assume the above code is okay, but want to confirm. Is the SDIO
> interrupt guaranteed to be on a worker thread?

Correct.

As a matter of fact, the sdio irqs can be delivered through a couple
of different paths. The legacy (scheduled for removal), is from a
dedicated kthread. The more "modern" way is either from the context of
a threaded IRQ handler or via a workqueue.

However, there are also so-called out of band SDIO irqs, typically
routed via a separate GPIO line. This isn't managed by the MMC/SDIO
subsystem, but the SDIO functional driver itself.

Kind regards
Uffe