Re: [PATCH 1/2] usb: ehci-exynos: Return immediately from suspend if ehci_suspend fails

From: Jingoo Han
Date: Wed Apr 09 2014 - 20:24:00 EST


On Thursday, April 10, 2014 3:32 AM, Alan Stern wrote:
> On Wed, 9 Apr 2014, Vivek Gautam wrote:
>
> > Patch 'b8efdaf USB: EHCI: add check for wakeup/suspend race'
> > adds a check for possible race between suspend and wakeup interrupt,
> > and thereby it returns -EBUSY as error code if there's a wakeup
> > interrupt.
> > So the platform host controller should not proceed further with
> > its suspend callback, rather should return immediately to avoid
> > powering down the essential things, like phy.
> >
> > Signed-off-by: Vivek Gautam <gautam.vivek@xxxxxxxxxxx>
> > Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> > Cc: Jingoo Han <jg1.han@xxxxxxxxxxx>
> > ---
> >
> > Based on 'usb-next' branch of Greg's usb tree.
> >
> > drivers/usb/host/ehci-exynos.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/host/ehci-exynos.c b/drivers/usb/host/ehci-exynos.c
> > index d1d8c47..a4550eb 100644
> > --- a/drivers/usb/host/ehci-exynos.c
> > +++ b/drivers/usb/host/ehci-exynos.c
> > @@ -212,6 +212,8 @@ static int exynos_ehci_suspend(struct device *dev)
> > int rc;
> >
> > rc = ehci_suspend(hcd, do_wakeup);
> > + if (rc)
> > + return rc;
> >
> > if (exynos_ehci->otg)
> > exynos_ehci->otg->set_host(exynos_ehci->otg, &hcd->self);
> > @@ -221,7 +223,7 @@ static int exynos_ehci_suspend(struct device *dev)
> >
> > clk_disable_unprepare(exynos_ehci->clk);
> >
> > - return rc;
> > + return 0;
> > }
> >
> > static int exynos_ehci_resume(struct device *dev)
>
> The first hunk of this patch is correct, but the second hunk isn't
> needed. A similar remark is true for the ehci-platform patch.

Hi Alan,

Do you mean the following?

1st hunk
+ if (rc)
+ return rc;

2nd hunk
- return rc;
+ return 0;

Currently, the 'rc' will be always 'zero'; however, I don't
Have any objection, because the code might be modified later.

Best regards,
Jingoo Han
>
> Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/