diff mbox

[RESEND,v2,1/7] usb: xhci: plat: Fix suspend/resume when the optional clk exists

Message ID 1461675460-2295-2-git-send-email-jszhang@marvell.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jisheng Zhang April 26, 2016, 12:57 p.m. UTC
Commit 4718c1774051 ("usb: host: xhci-plat: add clock support") adds
optional clk support, but it forgets to prepare/disable and
enable/unprepare the clk in the resume/suspend path. This path fixes
this issue by adding missing clk related calls.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Fixes: 4718c1774051 ("usb: host: xhci-plat: add clock support")
---
 drivers/usb/host/xhci-plat.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

Comments

Felipe Balbi April 27, 2016, 5:25 a.m. UTC | #1
Hi,

(since you're fixing somebody else's commit, it's nice to Cc authors)

Jisheng Zhang <jszhang@marvell.com> writes:
> Commit 4718c1774051 ("usb: host: xhci-plat: add clock support") adds
> optional clk support, but it forgets to prepare/disable and
                                          ^^^^^^^^^^^^^^^
                                          prepare/enable ?

> enable/unprepare the clk in the resume/suspend path. This path fixes
  ^^^^^^^^^^^^^^^^                                          ^^^^
  disable/unprepare ?                                       patch

> this issue by adding missing clk related calls.

frankly, I'm not sure this patch is entirely correct. At minimum, it's
not necessarily a bug fix. Original commit had no intent in gating
clocks during suspend/resume and, IMHO, that might not be what *all*
XHCI implementations want, though I'm not entirely sure.

> Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> Fixes: 4718c1774051 ("usb: host: xhci-plat: add clock support")

Assuming this is, indeed, a fix; you need to Cc stable here. Just add:

Cc: <stable@vger.kernel.org> # v3.16+

> ---
>  drivers/usb/host/xhci-plat.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 474b5fa..8cb46cb 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -295,6 +295,7 @@ static int xhci_plat_remove(struct platform_device *dev)
>  #ifdef CONFIG_PM_SLEEP
>  static int xhci_plat_suspend(struct device *dev)
>  {
> +	int ret;

this would look neater after hcd and xhci declarations below

>  	struct usb_hcd	*hcd = dev_get_drvdata(dev);
>  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
>  
> @@ -306,14 +307,25 @@ static int xhci_plat_suspend(struct device *dev)
>  	 * reconsider this when xhci_plat_suspend enlarges its scope, e.g.,
>  	 * also applies to runtime suspend.
>  	 */
> -	return xhci_suspend(xhci, device_may_wakeup(dev));
> +	ret = xhci_suspend(xhci, device_may_wakeup(dev));
> +	if (ret)
> +		return ret;
> +
> +	clk_disable_unprepare(xhci->clk);
> +
> +	return ret;
>  }
>  
>  static int xhci_plat_resume(struct device *dev)
>  {
> +	int ret;

ditto

>  	struct usb_hcd	*hcd = dev_get_drvdata(dev);
>  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
>  
> +	ret = clk_prepare_enable(xhci->clk);
> +	if (ret)
> +		return ret;
> +
>  	return xhci_resume(xhci, 0);
>  }
>  
> -- 
> 2.8.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Jisheng Zhang April 27, 2016, 5:46 a.m. UTC | #2
Dear Felipe,

On Wed, 27 Apr 2016 08:25:38 +0300 Felipe Balbi wrote:

> Hi,
> 
> (since you're fixing somebody else's commit, it's nice to Cc authors)
> 
> Jisheng Zhang <jszhang@marvell.com> writes:
> > Commit 4718c1774051 ("usb: host: xhci-plat: add clock support") adds
> > optional clk support, but it forgets to prepare/disable and  
>                                           ^^^^^^^^^^^^^^^
>                                           prepare/enable ?
> 
> > enable/unprepare the clk in the resume/suspend path. This path fixes  
>   ^^^^^^^^^^^^^^^^                                          ^^^^
>   disable/unprepare ?                                       patch
> 
> > this issue by adding missing clk related calls.  
> 
> frankly, I'm not sure this patch is entirely correct. At minimum, it's
> not necessarily a bug fix. Original commit had no intent in gating
> clocks during suspend/resume and, IMHO, that might not be what *all*
> XHCI implementations want, though I'm not entirely sure.

Thanks for the hint. Indeed, that's not all xhci-plat users want. I'll drop
this patch in v3.

Thanks a lot for the review,
Jisheng

> 
> > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > Fixes: 4718c1774051 ("usb: host: xhci-plat: add clock support")  
> 
> Assuming this is, indeed, a fix; you need to Cc stable here. Just add:
> 
> Cc: <stable@vger.kernel.org> # v3.16+
> 
> > ---
> >  drivers/usb/host/xhci-plat.c | 14 +++++++++++++-
> >  1 file changed, 13 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> > index 474b5fa..8cb46cb 100644
> > --- a/drivers/usb/host/xhci-plat.c
> > +++ b/drivers/usb/host/xhci-plat.c
> > @@ -295,6 +295,7 @@ static int xhci_plat_remove(struct platform_device *dev)
> >  #ifdef CONFIG_PM_SLEEP
> >  static int xhci_plat_suspend(struct device *dev)
> >  {
> > +	int ret;  
> 
> this would look neater after hcd and xhci declarations below
> 
> >  	struct usb_hcd	*hcd = dev_get_drvdata(dev);
> >  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> >  
> > @@ -306,14 +307,25 @@ static int xhci_plat_suspend(struct device *dev)
> >  	 * reconsider this when xhci_plat_suspend enlarges its scope, e.g.,
> >  	 * also applies to runtime suspend.
> >  	 */
> > -	return xhci_suspend(xhci, device_may_wakeup(dev));
> > +	ret = xhci_suspend(xhci, device_may_wakeup(dev));
> > +	if (ret)
> > +		return ret;
> > +
> > +	clk_disable_unprepare(xhci->clk);
> > +
> > +	return ret;
> >  }
> >  
> >  static int xhci_plat_resume(struct device *dev)
> >  {
> > +	int ret;  
> 
> ditto
> 
> >  	struct usb_hcd	*hcd = dev_get_drvdata(dev);
> >  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> >  
> > +	ret = clk_prepare_enable(xhci->clk);
> > +	if (ret)
> > +		return ret;
> > +
> >  	return xhci_resume(xhci, 0);
> >  }
> >  
> > -- 
> > 2.8.1
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html  
>
diff mbox

Patch

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 474b5fa..8cb46cb 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -295,6 +295,7 @@  static int xhci_plat_remove(struct platform_device *dev)
 #ifdef CONFIG_PM_SLEEP
 static int xhci_plat_suspend(struct device *dev)
 {
+	int ret;
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 
@@ -306,14 +307,25 @@  static int xhci_plat_suspend(struct device *dev)
 	 * reconsider this when xhci_plat_suspend enlarges its scope, e.g.,
 	 * also applies to runtime suspend.
 	 */
-	return xhci_suspend(xhci, device_may_wakeup(dev));
+	ret = xhci_suspend(xhci, device_may_wakeup(dev));
+	if (ret)
+		return ret;
+
+	clk_disable_unprepare(xhci->clk);
+
+	return ret;
 }
 
 static int xhci_plat_resume(struct device *dev)
 {
+	int ret;
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 
+	ret = clk_prepare_enable(xhci->clk);
+	if (ret)
+		return ret;
+
 	return xhci_resume(xhci, 0);
 }