Messages in this thread | | | Date | Fri, 26 Jul 2013 16:25:51 +0800 | From | Yijing Wang <> | Subject | Re: [PATCH -v3 3/3] PCI,pciehp: use PCIe DSN to identify device change during suspend |
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Hi Bjorn, Thanks for your review and comments!
> > I'm not sure this is implemented at the correct place. The idea of > using the serial number to detect card swaps is not really specific to > pciehp. I know the Device Serial Number capability is defined in the > PCIe spec, but it doesn't *require* any PCIe functionality, and > there's no reason a similar capability couldn't be defined for > conventional PCI.
Yes, maybe implement this interface in PCI core is better.
> > I don't know much about it, but conventional PCI *does* in fact > support the VPD capability, which can contain a serial number. I > wonder if we should enhance pci_device_serial_number() to look for a > VPD serial number if there's no PCIe DSN. Then we would want this > check for card swap in a more generic place, e.g., somewhere in > pci_scan_slot(), so all forms of hotplug would benefit from it.
This is a good idea, I will try to enhance pci_device_serial_number to support legacy PCI device VPD capability. Then I will try to move this to a more generic place.
> > Also, I think it's possible to use acpiphp for ExpressCard slots, and > this patch doesn't help acpiphp detect card swaps. I don't see any > mention of suspend/resume in acpiphp, so I don't know if it does > anything at all to detect card changes while suspended. Maybe Rafael > can shed some light?
Acpiphp driver is not attached to a specific pci/pcie device, so i think there is no point to call driver->suspend/resume interface. Add cc Rafael J. Wysocki.
> > I put the first two patches on a pci/yijing-dsn-v3 branch while we > work out the details of this one.
Thanks!
> > Bjorn > >> } else if (!list_empty(&pbus->devices)) { >> pciehp_disable_slot(slot); >> } >> -- >> 1.7.1 >> >> > > . >
-- Thanks! Yijing
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