Re: [PATCH -v2 2/3] PCI,pciehp: avoid add a device already exist before suspend during resume

From: Paul Bolle <pebolle@tiscali.nl>
To: Yijing Wang <wangyijing@huawei.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	Rafael <rjw@sisk.pl>, Hanjun Guo <guohanjun@huawei.com>,
	jiang.liu@huawei.com, Oliver Neukum <oneukum@suse.de>,
	Gu Zheng <guz.fnst@cn.fujitsu.com>
Subject: Re: [PATCH -v2 2/3] PCI,pciehp: avoid add a device already exist before suspend during resume
Date: Thu, 11 Jul 2013 16:27:39 +0200	[thread overview]
Message-ID: <1373552859.1349.9.camel@x61.thuisdomein> (raw)
In-Reply-To: <1373535825-49972-3-git-send-email-wangyijing@huawei.com>

On Thu, 2013-07-11 at 17:43 +0800, Yijing Wang wrote:
> Currently, pciehp_resume() try to hot add device if the slot adapter
> status return true. But if there are already some devices exist,
> namely list_empty(bus->devices) return false. We should not add the device
> again, because the device add action will fail. Also print some uncomfortable
> messages like this:
> 	pciehp 0000:00:1c.1:pcie04: Device 0000:03:00.0 already exists at 0000:03:00, cannot hot-add
> 	pciehp 0000:00:1c.1:pcie04: Cannot add device at 0000:03:00
> 
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> Cc: Paul Bolle <pebolle@tiscali.nl>
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> Cc: Oliver Neukum <oneukum@suse.de>
> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
> Cc: linux-pci@vger.kernel.org
> ---
>  drivers/pci/hotplug/pciehp_core.c |    9 ++++++---
>  1 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
> index 7d72c5e..1542735 100644
> --- a/drivers/pci/hotplug/pciehp_core.c
> +++ b/drivers/pci/hotplug/pciehp_core.c
[...]
> @@ -311,10 +312,12 @@ static int pciehp_resume (struct pcie_device *dev)
>  
>  	/* Check if slot is occupied */
>  	pciehp_get_adapter_status(slot, &status);
> -	if (status)
> -		pciehp_enable_slot(slot);
> -	else
> +	if (status) {
> +		if (list_empty(&pbus->devices))
> +			pciehp_enable_slot(slot);
> +	} else if (!list_empty(&pbus->devices))
>  		pciehp_disable_slot(slot);
> +

Coding style: braces for the "else if" branch too? Or change the first
test to "if (status && list_empty([...]))" and drop the braces?

>  	return 0;
>  }
>  #endif /* PM */

Paul Bolle