On Monday, March 26, 2018 7:54:35 AM CEST Kai Heng Feng wrote:
Hi Bjorn, Rafael,
On Mar 19, 2018, at 10:09 PM, Kai-Heng Feng kai.heng.feng@canonical.com 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-
Before commit de3ef1eb1cd0, the device never gets runtime suspended. After that 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@vger.kernel.org # 4.13+ Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com
Is there any improvement I can address? Or do you have any concern about this patch?
Kai-Heng
v2: Explicitly check dev->pme_support.
drivers/pci/pci.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f6a4dd10d9b0..52821a21fc07 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2125,16 +2125,16 @@ 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;
/* 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)))
So why do you change 'false' to 'true' here?
At least that change should be mentioned in the changelog too.
return false;
- if (device_can_wakeup(&dev->dev))
return true;- while (bus->parent) { struct pci_dev *bridge = bus->self;