Re: [PATCH 1/3] i2c: bcm2835: Use platform_get_irq() to get the interrupt

[Florian Fainelli]

On 12/19/2021 1:52 AM, Lad, Prabhakar wrote:
> Hi Florian,
>
> On Sat, Dec 18, 2021 at 10:44 PM Lad, Prabhakar
> <prabhakar.csengg@xxxxxxxxx> wrote:
> > Hi Florian,
> >
> > Thank you for the review.
> >
> > On Sat, Dec 18, 2021 at 9:17 PM Florian Fainelli <f.fainelli@xxxxxxxxx> wrote:
> > > On 12/18/2021 8:52 AM, Lad Prabhakar wrote:
> > > > platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> > > > allocation of IRQ resources in DT core code, this causes an issue
> > > > when using hierarchical interrupt domains using "interrupts" property
> > > > in the node as this bypasses the hierarchical setup and messes up the
> > > > irq chaining.
> > > >
> > > > In preparation for removal of static setup of IRQ resource from DT core
> > > > code use platform_get_irq().
> > > >
> > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > >
> > > Just one nit below:
> > > > ---
> > > >    drivers/i2c/busses/i2c-bcm2835.c | 11 ++++-------
> > > >    1 file changed, 4 insertions(+), 7 deletions(-)
> > > >
> > > > diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
> > > > index 37443edbf754..d63dec5f3cb1 100644
> > > > --- a/drivers/i2c/busses/i2c-bcm2835.c
> > > > +++ b/drivers/i2c/busses/i2c-bcm2835.c
> > > > @@ -402,7 +402,7 @@ static const struct i2c_adapter_quirks bcm2835_i2c_quirks = {
> > > >    static int bcm2835_i2c_probe(struct platform_device *pdev)
> > > >    {
> > > >        struct bcm2835_i2c_dev *i2c_dev;
> > > > -     struct resource *mem, *irq;
> > > > +     struct resource *mem;
> > > >        int ret;
> > > >        struct i2c_adapter *adap;
> > > >        struct clk *mclk;
> > > > @@ -452,12 +452,9 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
> > > >                return ret;
> > > >        }
> > > >
> > > > -     irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> > > > -     if (!irq) {
> > > > -             dev_err(&pdev->dev, "No IRQ resource\n");
> > > > -             return -ENODEV;
> > > > -     }
> > > > -     i2c_dev->irq = irq->start;
> > > > +     i2c_dev->irq = platform_get_irq(pdev, 0);
> > > > +     if (i2c_dev->irq <= 0)
> > > > +             return i2c_dev->irq ? i2c_dev->irq : -ENXIO;
> > >
> > > Why not just check for a negative return code and propagate it as is?
> > platform_get_irq() may return 0 said that we do get a splat in this
> > case and further request_irq() will fail so instead check it here.
> My bad, just the negative check should suffice.

Think so too, looking forward to v2, thanks!
--
Florian