[PATCH v2 20/22] usb: host: xhci-mtk: deny IRQ0

[Chunfeng Yun]

On Wed, 2021-10-27 at 12:25 +0300, Sergey Shtylyov wrote:
> On 27.10.2021 12:18, Chunfeng Yun wrote:
> 
> > > If platform_get_irq() returns IRQ0 (considered invalid according
> > > to
> > > Linus)
> > > the driver blithely passes it to usb_add_hcd() that treats IRQ0
> > > as no
> > > IRQ
> > > at all. Deny IRQ0 right away, returning -EINVAL from the probe()
> > > method...
> > > 
> > > Fixes: 0cbd4b34cda9 ("xhci: mediatek: support MTK xHCI host
> > > controller")
> > > Signed-off-by: Sergey Shtylyov <s.shtylyov at omp.ru>
> > > ---
> > >   drivers/usb/host/xhci-mtk.c | 4 +++-
> > >   1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-
> > > mtk.c
> > > index c53f6f276d5c..d2dc8d9863ee 100644
> > > --- a/drivers/usb/host/xhci-mtk.c
> > > +++ b/drivers/usb/host/xhci-mtk.c
> > > @@ -495,7 +495,7 @@ static int xhci_mtk_probe(struct
> > > platform_device
> > > *pdev)
> > >   		return ret;
> > >   
> > >   	irq = platform_get_irq_byname_optional(pdev, "host");
> > > -	if (irq < 0) {
> > > +	if (irq <= 0) {
> > >   		if (irq == -EPROBE_DEFER)
> > >   			return irq;
> > >   
> > > @@ -503,6 +503,8 @@ static int xhci_mtk_probe(struct
> > > platform_device
> > > *pdev)
> > >   		irq = platform_get_irq(pdev, 0);
Here, irq is updated again

> > >   		if (irq < 0)
> > >   			return irq;
> > > +		if (!irq)
> > 
> > it's "if (irq <= 0)"?
> 
>     No, if (irq == 0).
> 
> > > +			return -EINVAL;
add "else if (irq < 0), return irq;"?  but not -EINVAL only, this may
drop EPROBE_DEFER

> > >   	}
> > >   
> > >   	wakeup_irq = platform_get_irq_byname_optional(pdev,
> > > "wakeup");
> 
> MBR, Sergey