Re: [PATCH v2] usb: hub: Prevent hub autosuspend if usbcore.autosuspend is -1

From: Roger Quadros
Date: Thu Aug 28 2014 - 05:52:32 EST


On 08/28/2014 12:02 AM, Greg KH wrote:
> On Wed, Aug 27, 2014 at 12:23:39PM -0700, Greg KH wrote:
>> On Wed, Aug 27, 2014 at 03:11:10PM +0300, Roger Quadros wrote:
>>> If user specifies that USB autosuspend must be disabled by module
>>> parameter "usbcore.autosuspend=-1" then we must prevent
>>> autosuspend of USB hub devices as well.
>>>
>>> commit 596d789a211d introduced in v3.8 changed the original behaivour
>>> and stopped respecting the usbcore.autosuspend parameter for hubs.
>>>
>>> Fixes: 596d789a211d "USB: set hub's default autosuspend delay as 0"
>>>
>>> Cc: [3.8+] <stable@xxxxxxxxxxxxxxx>
>>> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
>>> ---
>>> drivers/usb/core/hub.c | 8 +++++++-
>>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
>>> index 8a4dcbc..59b599d 100644
>>> --- a/drivers/usb/core/hub.c
>>> +++ b/drivers/usb/core/hub.c
>>> @@ -1728,8 +1728,14 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
>>> * - Change autosuspend delay of hub can avoid unnecessary auto
>>> * suspend timer for hub, also may decrease power consumption
>>> * of USB bus.
>>> + *
>>> + * - If user has indicated to prevent autosuspend by passing
>>> + * usbcore.autosuspend = -1 then keep autosuspend disabled.
>>> */
>>> - pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
>>> +#ifdef CONFIG_PM_RUNTIME
>>> + if (hdev->dev.power.autosuspend_delay >= 0)
>>> + pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
>>> +#endif
>>>
>>> /*
>>> * Hubs have proper suspend/resume support, except for root hubs
>>
>> Sorry, but can I have a patch that just adds the #ifdef as I already
>> have your original one in my tree.
>
> This should be all that is needed, right?
>
> ---------
>
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 003cb6b1a6bf..46f5161c7891 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -1732,8 +1732,10 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
> * - If user has indicated to prevent autosuspend by passing
> * usbcore.autosuspend = -1 then keep autosuspend disabled.
> */
> +#ifdef CONFIG_PM_RUNTIME
> if (hdev->dev.power.autosuspend_delay >= 0)
> pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
> +#endif
>
> /*
> * Hubs have proper suspend/resume support, except for root hubs
>

Yes. Thanks Greg.

cheers,
-roger
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