Re: [PATCH v6 2/2] can: m_can: Add hrtimer to generate software interrupt

[Judith Mendez <jm@xxxxxx>]

Hello,

On 5/22/23 1:37 PM, Marc Kleine-Budde wrote:
> On 22.05.2023 10:17:38, Judith Mendez wrote:
> > > > diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
> > > > index 94dc82644113..3e60cebd9d12 100644
> > > > --- a/drivers/net/can/m_can/m_can_platform.c
> > > > +++ b/drivers/net/can/m_can/m_can_platform.c
> > > > @@ -5,6 +5,7 @@
> > > >    //
> > > >    // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
> > > > +#include <linux/hrtimer.h>
> > > >    #include <linux/phy/phy.h>
> > > >    #include <linux/platform_device.h>
> > > > @@ -96,12 +97,40 @@ static int m_can_plat_probe(struct platform_device *pdev)
> > > >    		goto probe_fail;
> > > >    	addr = devm_platform_ioremap_resource_byname(pdev, "m_can");
> > > > -	irq = platform_get_irq_byname(pdev, "int0");
> > > > -	if (IS_ERR(addr) || irq < 0) {
> > > > -		ret = -EINVAL;
> > > > +	if (IS_ERR(addr)) {
> > > > +		ret = PTR_ERR(addr);
> > > >    		goto probe_fail;
> > > >    	}
> > >
> > > As we don't use an explicit "poll-interval" anymore, this needs some
> > > cleanup. The flow should be (pseudo code, error handling omitted):
> > >
> > > if (device_property_present("interrupts") {
> > >           platform_get_irq_byname();
> > >           polling = false;
> > > } else {
> > >           hrtimer_init();
> > >           polling = true;
> > > }
> >
> > Ok.
> >
> > > > +	irq = platform_get_irq_byname_optional(pdev, "int0");
> > >
> > > Remove the "_optional" and....
> >
> > On V2, you asked to add the _optional?.....
> >
> > >   	irq = platform_get_irq_byname(pdev, "int0");
> >
> > use platform_get_irq_byname_optional(), it doesn't print an error
> > message.
>
> ACK - I said that back in v2, when there was "poll-interval". But now we
> don't use "poll-interval" anymore, but test if interrupt properties are
> present.
>
> See again pseudo-code I posted in my last mail:
>
> | if (device_property_present("interrupts") {
> |          platform_get_irq_byname();
>
> If this throws an error, it's fatal, bail out.
>
> |          polling = false;
> | } else {
> |          hrtimer_init();
> |          polling = true;
> | }

Ok, will add this then..


> > > > +	if (irq == -EPROBE_DEFER) {
> > > > +		ret = -EPROBE_DEFER;
> > > > +		goto probe_fail;
> > > > +	}
> > > > +
> > > > +	if (device_property_present(mcan_class->dev, "interrupts") ||
> > > > +	    device_property_present(mcan_class->dev, "interrupt-names"))
> > > > +		mcan_class->polling = false;
> > >
> > > ...move the platform_get_irq_byname() here
> >
> > ok,
> >
> > > > +	else
> > > > +		mcan_class->polling = true;
> > > > +
> > > > +	if (!mcan_class->polling && irq < 0) {
> > > > +		ret = -ENXIO;
> > > > +		dev_err_probe(mcan_class->dev, ret, "IRQ int0 not found, polling not activated\n");
> > > > +		goto probe_fail;
> > > > +	}
> > >
> > > Remove this check.
> >
> > Should we not go to 'probe fail' if polling is not activated and irq is not
> > found?
>
> If an interrupt property is present in the DT, we use it - if request
> IRQ fails, something is broken and we've already bailed out. See above.
> If there is no interrupt property we use polling.

Got it, thanks.

> > > > +
> > > > +	if (mcan_class->polling) {
> > > > +		if (irq > 0) {
> > > > +			mcan_class->polling = false;
> > > > +			dev_info(mcan_class->dev, "Polling enabled, using hardware IRQ\n");
> > >
> > > Remove this.
> >
> > Remove the dev_info?
>
> ACK, this is not possible anymore - we cannot have polling enabled and
> HW IRQs configured.

Sounds good, will submit a v7 with these cleanup changes.

regards,
Judith