Re: [PATCH v10 5/5] usb: dwc3: core: cleanup IRQ resources

[Sergei Shtylyov]

On 6/10/2016 2:46 PM, Roger Quadros wrote:

> > > > > Implementations might use different IRQs for
> > > > > host, gadget so use named interrupt resources
> > > > > to allow device tree to specify the interrupts.
> > > > >
> > > > > Following are the interrupt names
> > > > >
> > > > > Peripheral Interrupt - peripheral
> > > > > HOST Interrupt - host
> > > > >
> > > > > Maintain backward compatibility for a single named
> > > > > interrupt ("dwc3_usb3") for all interrupts as well as
> > > > > unnamed interrupt at index 0 for all interrupts.
> > > > >
> > > > > As platform_get_irq_() variants are used, tackle
> > > >
> > > >    platform_get_irq().
> > >
> > > OK.
> > > > > the -EPROBE_DEFER case as well.
> > > > >
> > > > > Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> > > > > ---
> > > > > v10:
> > > > > - don't mention otg irq since we are not using it yet
> > > > > - use platform_get_irq() and friends and check -EPROBE_DEFER case.
> > > > >
> > > > >  drivers/usb/dwc3/core.c   | 22 ++++++++--------------
> > > > >  drivers/usb/dwc3/gadget.c | 29 ++++++++++++++++++++++++++---
> > > > >  drivers/usb/dwc3/host.c   | 41 ++++++++++++++++++++++++++++++++++++++++-
> > > > >  3 files changed, 74 insertions(+), 18 deletions(-)
> > > > >
> > > > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > > > > index 8fceeb1..131e7eb 100644
> > > > > --- a/drivers/usb/dwc3/core.c
> > > > > +++ b/drivers/usb/dwc3/core.c
> > > > [...]
> > > > > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> > > > > index 0f6fb8e..774a0d8 100644
> > > > > --- a/drivers/usb/dwc3/gadget.c
> > > > > +++ b/drivers/usb/dwc3/gadget.c
> > > > [...]
> > > > > @@ -2866,7 +2865,31 @@ static irqreturn_t dwc3_interrupt(int irq, void *_evt)
> > > > >   */
> > > > >  int dwc3_gadget_init(struct dwc3 *dwc)
> > > > >  {
> > > > > -    int                    ret;
> > > > > +    int ret, irq;
> > > > > +    struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
> > > > > +
> > > > > +    irq = platform_get_irq_byname(dwc3_pdev, "peripheral");
> > > > > +    if (irq == -EPROBE_DEFER)
> > > > > +        return irq;
> > > > > +
> > > > > +    if (irq <= 0) {
> > > > > +        irq = platform_get_irq_byname(dwc3_pdev, "dwc_usb3");
> > > > > +        if (irq == -EPROBE_DEFER)
> > > > > +            return irq;
> > > > > +
> > > > > +        if (irq <= 0) {
> > > > > +            irq = platform_get_irq(dwc3_pdev, 0);
> > > > > +            if (irq <= 0) {
> > > > > +                if (irq != -EPROBE_DEFER) {
> > > > > +                    dev_err(dwc->dev,
> > > > > +                        "missing peripheral IRQ\n");
> > > > > +                }
> > > > > +                return irq;
> > > >
> > > >    Iff irq == 0, you'll return success despite IRQ was "invalid". Was that intended?
> > >
> > > good catch. It wasn't intended. I guess i'll return -EINVAL then?

[...]

> >    I'd just consider 0 a valid IRQ, that's simpler. FYI, I've submitted to Greg KH a patch fixing platform_get_irq[_byname]() to not return 0 on failure. No reaction so far...
>
> Maybe till your patch is in we can't really differentiate if it is error or not
> so it is safer to consider it as error IMO.

   Returning -EINVAL is fine then.

> cheers,
> -roger

MBR, Sergei