lkml.org 
[lkml]   [2013]   [Jul]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH -v2 3/3] PCI,pciehp: use PCIe DSN to identify device change during suspend
Sorry, did a 'reply' instead of 'reply all' on first reply to this patch...
excuse any repeat...
- Don

On 07/11/2013 05:43 AM, Yijing Wang wrote:
> If device was removed from slot and reinsert a new device during
> suspend, pciehp can not identify the physical device change now.
> So the old driver .resume() method will be called for the new device,
> this is bad. If device support device serial number capability,
> we can identify this by DSN. So the reasonable way is first remove
> the old device, then enable the new device.
>
> 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 | 45 +++++++++++++++++++++++++++++++++++++
> 1 files changed, 45 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
> index 1542735..f2eb214 100644
> --- a/drivers/pci/hotplug/pciehp_core.c
> +++ b/drivers/pci/hotplug/pciehp_core.c
> @@ -296,11 +296,38 @@ static int pciehp_suspend (struct pcie_device *dev)
> return 0;
> }
>
> +/*
> + * check the func 0 device serial number is changed,
> + * if device does not support device serial number,
> + * return false.
> + */
> +static bool device_serial_number_changed(struct pci_bus *pbus)
> +{
> + u64 old_dsn, new_dsn;
> + struct pci_dev *pdev;
> +
> + pdev = pci_get_slot(pbus, PCI_DEVFN(0, 0));
> + if (!pdev)
> + return false;
> +
> + old_dsn = pdev->sn;
> +
> + /* get func 0 device serial number */
> + new_dsn = pci_device_serial_number(pdev);
Due to previous recommended change to 1/3 patch, above would be:
pci_device_serial_number(pdev);

> + pci_dev_put(pdev);
> +
> + if (old_dsn != new_dsn)
> + return true;
> +
and above would be:
new_dsn = pdev->dsn;
pci_dev_put(pdev);
if(pdev->dsn != old_dsn)
return true;

> + return false;
> +}
> +
> static int pciehp_resume (struct pcie_device *dev)
> {
> struct controller *ctrl;
> struct slot *slot;
> struct pci_bus *pbus = dev->port->subordinate;
> + int retval = 0;
> u8 status;
>
> ctrl = get_service_data(dev);
> @@ -315,6 +342,24 @@ static int pciehp_resume (struct pcie_device *dev)
> if (status) {
> if (list_empty(&pbus->devices))
> pciehp_enable_slot(slot);
> +
> + if (device_serial_number_changed(pbus)) {
> + /*
> + * first power off slot, avoid the old driver
> + * .remove() method touch the new hardware
> + */
> + if (POWER_CTRL(ctrl)) {
> + retval = pciehp_power_off_slot(slot);
> + if (retval) {
> + ctrl_err(ctrl,
> + "Issue of Slot Disable command failed\n");
> + return 0;
> + }
> + msleep(1000);
> + pciehp_unconfigure_device(slot);
> + pciehp_enable_slot(slot);
> + }
> + }
> } else if (!list_empty(&pbus->devices))
> pciehp_disable_slot(slot);
>



\
 
 \ /
  Last update: 2013-07-11 16:42    [W:0.155 / U:2.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site