Re: [PATCH V2 2/3] gpio: xilinx: Add interrupt support

[Andy Shevchenko]

On Fri, Jul 24, 2020 at 8:15 PM Srinivas Neeli <sneeli@xxxxxxxxxx> wrote:

...

> > > +#include <linux/irqchip/chained_irq.h>
> >
> > Not sure I see a user of it.
> >
> > ...
> we are using chained_irq_enter() and chained_irq_exit()
> APIs , so need "chained_irq.h"

I see.  But gpio/driver.h does it for you.

...

> > > +       for (index = 0; index < num_channels; index++) {
> > > +               if ((status & BIT(index))) {
> >
> > If gpio_width is the same among banks, you can use for_each_set_bit()
> > here as well.
> >
> > ...
> gpio_wdith vary depends on design. We can configure gpio pins for each bank.

I see.

...

> > > +       chip->irq = platform_get_irq_optional(pdev, 0);
> > > +       if (chip->irq <= 0) {
> > > +               dev_info(&pdev->dev, "GPIO IRQ not set\n");
> >
> > Why do you need an optional variant if you print an error anyway?
>
> Here intention is just printing a debug message to user.

Debug message should be debug, and not info. But in any case, I would
rather drop it, or use platform_get_irq() b/c now you have a code
controversy.

...

> > > +               chip->gc.irq.parents = (unsigned int *)&chip->irq;
> > > +               chip->gc.irq.num_parents = 1;
> >
> > Current pattern is to use devm_kcalloc() for it (Linus has plans to
> > simplify this in the future and this will help him to find what
> > patterns are being used)
>
> I didn't get this , Could you please explain more.

              girq->num_parents = 1;
              girq->parents = devm_kcalloc(dev, girq->num_parents, ...);
   if (!girq->parents)
     return -ENOMEM;

girq->parents[0] = chip->irq;

Also, use temporary variable for IRQ chip structure:
 girq = &chip->gc.irq;


-- 
With Best Regards,
Andy Shevchenko