[+cc Mika, Rafael] On Fri, May 13, 2016 at 01:15:31PM +0200, Lukas Wunner wrote: > If a hotplug port is suspended to D3cold, its slot status register > cannot be read. If that hotplug port happens to share its IRQ with > other devices, then whenever an interrupt occurs for one of these > devices, a "no response from device" message is logged with level > KERN_INFO. Apart from this annoyance, CPU time is needlessly spent > trying to read the slot status register even though we know in advance > that it will fail. I guess this is a pretty generic problem that could affect any device that shares an IRQ. I think I'll queue this on my pci/pm branch, since it seems closely related to Mika's "PCI: Add runtime PM support for PCIe ports". Did you check for the same issue in other likely places, e.g., AER, PME, etc.? > On MacBook Pros introduced 2011 and 2012, the IRQ of a Thunderbolt > hotplug port is unfortunately shared with a wireless card, an audio card > and an SDXC controller. When the Thunderbolt controller is powered > down, the machine carries out at least one unneeded slot status register > read for each wireless packet received and prints a corresponding error > message to the system log. > > The hotplug port's current_state will be D3cold when it's powered down, > so ignore interrupts that occur during that power state. > > Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> > --- > drivers/pci/hotplug/pciehp_hpc.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c > index 5c24e93..08e84d6 100644 > --- a/drivers/pci/hotplug/pciehp_hpc.c > +++ b/drivers/pci/hotplug/pciehp_hpc.c > @@ -546,6 +546,10 @@ static irqreturn_t pcie_isr(int irq, void *dev_id) > u8 present; > bool link; > > + /* Interrupts cannot originate from a controller that's asleep */ > + if (pdev->current_state == PCI_D3cold) > + return IRQ_NONE; > + > /* > * In order to guarantee that all interrupt events are > * serviced, we need to re-inspect Slot Status register after > -- > 2.8.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
