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

From: Alan Stern
Date: Wed Apr 09 2014 - 14:33:16 EST


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.

Alan Stern

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