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From: =?utf-8?Q?Bj=C3=B8rn_Mork?= <bjorn@mork.no>
To: Huang Ying <ying.huang@intel.com>
Cc: huang ying <huang.ying.caritas@gmail.com>,
	"Rafael J. Wysocki" <rjw@sisk.pl>,
	Zheng Yan <zheng.z.yan@intel.com>,
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Subject: Re: bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure
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Date: Fri, 27 Jul 2012 11:11:47 +0200
In-Reply-To: <1343367309.3874.21.camel@yhuang-dev> (Huang Ying's message of
	"Fri, 27 Jul 2012 13:35:09 +0800")
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Huang Ying <ying.huang@intel.com> writes:

> Do you have time to try the following patch?
>
> Best Regards,
> Huang Ying
>
> ---
>  drivers/pci/pci-driver.c |    6 ++++++
>  1 file changed, 6 insertions(+)
>
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi)
>  {
>  	struct drv_dev_and_id *ddi = _ddi;
>  	struct device *dev = &ddi->dev->dev;
> +	struct device *parent = dev->parent;
>  	int rc;
>  
> +	/* The parent bridge must be in active state when probing */
> +	if (parent)
> +		pm_runtime_get_sync(parent);
>  	/* Unbound PCI devices are always set to disabled and suspended.
>  	 * During probe, the device is set to enabled and active and the
>  	 * usage count is incremented.  If the driver supports runtime PM,
> @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi)
>  		pm_runtime_set_suspended(dev);
>  		pm_runtime_put_noidle(dev);
>  	}
> +	if (parent)
> +		pm_runtime_put(parent);
>  	return rc;
>  }
>  


Yup, that worked in the quick test I just did.

 lspci reading the device config will still not wake the bridge, but I
assume that is intentional?  But loading the device driver now wakes
both the bridge and the device, so that works.


Bjørn