Re: [PATCH v4 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC

From: Sagar Kadam
Date: Mon May 20 2019 - 09:30:29 EST


Hi Andrew,

On Mon, May 20, 2019 at 6:11 PM Andrew Lunn <andrew@xxxxxxx> wrote:
>
> > @@ -406,7 +416,7 @@ static int ocores_xfer(struct i2c_adapter *adap,
> > {
> > struct ocores_i2c *i2c = i2c_get_adapdata(adap);
> >
> > - if (i2c->flags & OCORES_FLAG_POLL)
> > + if ((i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ)))
> > return ocores_xfer_polling(adap, msgs, num);
> > return ocores_xfer_core(i2c, msgs, num, false);
> > }
>
> You are not listening to what i said. All you need to know here is
> that you must poll. It does not matter if the IRQ is broken or not.
>

Apologies for my miss-understanding. I will rectify this and submit a v5.

> > irq = platform_get_irq(pdev, 0);
> > if (irq == -ENXIO) {
> > - i2c->flags |= OCORES_FLAG_POLL;
>
> If there is no interrupt, you need to poll. So keep this line.

Will retain this.

> > + /*
> > + * Set a OCORES_FLAG_BROKEN_IRQ to enable workaround for
> > + * FU540-C000 SoC in polling mode interface of i2c-ocore driver.
> > + * Else enable default polling mode interface for SIFIVE/OCORE
> > + * device types.
> > + */
> > + match = of_match_node(ocores_i2c_match, pdev->dev.of_node);
> > + if (match && (long)match->data == TYPE_SIFIVE_REV0)
> > + i2c->flags |= OCORES_FLAG_BROKEN_IRQ;
>
> If it is a OCORE, IRQ is broken, so OR in OCORES_FLAG_BROKEN_IRQ.

Got it, as device type SIFIVE is based on OCORE's re-implementation,
will OR in the broken IRQ flag and submit a v5.

> >
> > - if (!(i2c->flags & OCORES_FLAG_POLL)) {
> > + if (!(i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ))) {
> > ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0,
> > pdev->name, i2c);
>
> Here you just need to know if you are polling. Broken IRQ does not
> matter.
>
> Andrew

Thanks & Regards,
Sagar