On Sunday, March 18, 2018 8:12:15 PM CET Kai-Heng Feng wrote:
> USB controller ASM1042 stops working after commit de3ef1eb1cd0 ("PM /
> core: Drop run_wake flag from struct dev_pm_info").
>
> The device in question is not power managed by platform firmware,
> furthermore, it only supports PME# from D3cold:
> Capabilities: [78] Power Management version 3
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0-,D1-,D2-,D3hot-,D3cold+)
> Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
That's somewhat unusual, but OK.
> Before the commit, the device never gets runtime suspended. After the
> commit, the device gets runtime suspended, so it does not respond to any
> PME#.
>
> usb_hcd_pci_probe() mandatorily calls device_wakeup_enable(), hence
> device_can_wakeup() in pci_dev_run_wake() always returns true.
>
> So pci_dev_run_wake() needs to check PME wakeup capability as its first
> condition.
>
> Fixes: de3ef1eb1cd0 ("PM / core: Drop run_wake flag from struct dev_pm_info")
> Cc: stable@xxxxxxxxxxxxxxx # 4.13+
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> ---
> drivers/pci/pci.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index f6a4dd10d9b0..e026d8f313ec 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2125,16 +2125,13 @@ bool pci_dev_run_wake(struct pci_dev *dev)
> {
> struct pci_bus *bus = dev->bus;
>
> - if (device_can_wakeup(&dev->dev))
> - return true;
> -
> - if (!dev->pme_support)
> - return false;
Why are you removing this check?
> -
> /* PME-capable in principle, but not from the target power state */
> - if (!pci_pme_capable(dev, pci_target_state(dev, false)))
> + if (!pci_pme_capable(dev, pci_target_state(dev, true)))
> return false;
>
> + if (device_can_wakeup(&dev->dev))
> + return true;
> +
> while (bus->parent) {
> struct pci_dev *bridge = bus->self;
>
>
Thanks,
Rafael
