2014-04-09 04:01:01

by Vivek Gautam

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

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 <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Jingoo Han <[email protected]>
---

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)
--
1.7.10.4


2014-04-09 04:01:06

by Vivek Gautam

[permalink] [raw]
Subject: [PATCH 2/2] usb: ehci-platform: Return immediately from suspend if ehci_suspend fails

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 <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Hauke Mehrtens <[email protected]>
Cc: Hans de Goede <[email protected]>
---

Based on 'usb-next' branch of Greg's usb tree.

drivers/usb/host/ehci-platform.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index b3a0e11..60d3d1a 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -303,11 +303,13 @@ static int ehci_platform_suspend(struct device *dev)
int ret;

ret = ehci_suspend(hcd, do_wakeup);
+ if (ret)
+ return ret;

if (pdata->power_suspend)
pdata->power_suspend(pdev);

- return ret;
+ return 0;
}

static int ehci_platform_resume(struct device *dev)
--
1.7.10.4

2014-04-09 05:01:55

by Jingoo Han

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

On Wednesday, April 09, 2014 1:01 PM, 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 <[email protected]>
> Cc: Alan Stern <[email protected]>
> Cc: Jingoo Han <[email protected]>

Acked-by: Jingoo Han <[email protected]>

Best regards,
Jingoo Han

> ---
>
> 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)
> --
> 1.7.10.4

2014-04-09 18:32:14

by Alan Stern

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

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 <[email protected]>
> Cc: Alan Stern <[email protected]>
> Cc: Jingoo Han <[email protected]>
> ---
>
> 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

2014-04-10 00:23:52

by Jingoo Han

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

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 <[email protected]>
> > Cc: Alan Stern <[email protected]>
> > Cc: Jingoo Han <[email protected]>
> > ---
> >
> > 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

2014-04-10 01:36:16

by Alan Stern

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

On Thu, 10 Apr 2014, Jingoo Han wrote:

> > > --- 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;

Yes, that's what I mean.

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

Exactly. We should add the new "if" statement but leave the "return
rc" the way it is.

Alan Stern

2014-04-10 05:31:15

by Vivek Gautam

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

Hi Alan,


On Thu, Apr 10, 2014 at 7:06 AM, Alan Stern <[email protected]> wrote:
> On Thu, 10 Apr 2014, Jingoo Han wrote:
>
>> > > --- 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;
>
> Yes, that's what I mean.
>
>> Currently, the 'rc' will be always 'zero'; however, I don't
>> Have any objection, because the code might be modified later.
>
> Exactly. We should add the new "if" statement but leave the "return
> rc" the way it is.

Sure, i will update both the patches.

>
> Alan Stern
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html