Re: [PATCH v9 4/5] usb: ehci: Add new EHCI driver for Broadcom STB SoC's

From: Alan Cooper
Date: Tue May 12 2020 - 10:24:24 EST


On Mon, May 11, 2020 at 3:51 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Mon, 11 May 2020, Al Cooper wrote:
>
> > Add a new EHCI driver for Broadcom STB SoC's. A new EHCI driver
> > was created instead of adding support to the existing ehci platform
> > driver because of the code required to work around bugs in the EHCI
> > controller. The primary workaround is for a bug where the Core
> > violates the SOF interval between the first two SOFs transmitted after
> > resume. This only happens if the resume occurs near the end of a
> > microframe. The fix is to intercept the ehci-hcd request to complete
> > RESUME and align it to the start of the next microframe.
> >
> > Signed-off-by: Al Cooper <alcooperx@xxxxxxxxx>
> > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> > Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> > ---
>
> I hate to point this out...
>
> > +static int ehci_brcm_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct resource *res_mem;
> > + struct brcm_priv *priv;
> > + struct usb_hcd *hcd;
> > + int irq;
> > + int err;
> > +
> > + err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
> > + if (err)
> > + return err;
> > +
> > + irq = platform_get_irq(pdev, 0);
> > + if (irq <= 0)
> > + return irq ? irq : EINVAL;
>
> That should be -EINVAL.
>
> To tell the truth, I'm not sure it's worthwhile checking for irq == 0.
> That's up to Greg to decide.

Darn, I've been looking at this code for too long :(
Since Greg originally requested <=, I'll fix this and send v10.

Thanks
Al

>
> Anyway, as far as I'm concerned you can either change EINVAL to -EINVAL
> or change the whole thing back to "if (irq < 0) return irq;". Either
> way, you may add:
>
> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
>
> Alan Stern
>