| Message ID | 47f9e4a9ca09e854d2d01812a4c05b7c6df02259.1463134231.git.lukas@wunner.de (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Fri, May 13, 2016 at 01:15:31PM +0200, Lukas Wunner wrote: > Thunderbolt controllers have a pin to signal plug events while the > controller is powered down. On Macs this pin is wired to the > southbridge and causes a GPE to be fired. The OS may then power up the > controller to probe the newly connected device. It is thus okay to let > Thunderbolt hotplug ports go to D3 on Macs. > > Signed-off-by: Lukas Wunner <lukas@wunner.de> > --- > drivers/pci/pcie/portdrv_pci.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c > index f75d4b5..7860ab3 100644 > --- a/drivers/pci/pcie/portdrv_pci.c > +++ b/drivers/pci/pcie/portdrv_pci.c > @@ -224,9 +224,12 @@ static int pcie_portdrv_probe(struct pci_dev *dev, > * to enumerate devices behind this port properly (the port is > * powered down preventing all config space accesses to the > * subordinate devices). We can't be sure for native PCIe hotplug > - * either so prevent that as well. > + * either so prevent that as well. However Thunderbolt controllers > + * on Macs are capable of side-band signaling plug events while > + * powered down, so allow them to suspend. > */ > - if (!dev->is_hotplug_bridge) { > + if (!dev->is_hotplug_bridge || > + (dev->is_thunderbolt && dmi_match(DMI_SYS_VENDOR, "Apple Inc."))) { I'd rather have a bit in the pci_dev to control this. I don't know how this would be different from the recently-added "bridge_d3" bit. The bit could be set by a quirk. It'd be nice if it were a single bit so we don't have to test is_hotplug_bridge *and* another bit. > /* > * Keep the port resumed 10ms to make sure things like > * config space accesses from userspace (lspci) will not > @@ -243,7 +246,8 @@ static int pcie_portdrv_probe(struct pci_dev *dev, > > static void pcie_portdrv_remove(struct pci_dev *dev) > { > - if (!dev->is_hotplug_bridge) { > + if (!dev->is_hotplug_bridge || > + (dev->is_thunderbolt && dmi_match(DMI_SYS_VENDOR, "Apple Inc."))) { > pm_runtime_forbid(&dev->dev); > pm_runtime_get_noresume(&dev->dev); > pm_runtime_dont_use_autosuspend(&dev->dev); > -- > 2.8.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index f75d4b5..7860ab3 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -224,9 +224,12 @@ static int pcie_portdrv_probe(struct pci_dev *dev, * to enumerate devices behind this port properly (the port is * powered down preventing all config space accesses to the * subordinate devices). We can't be sure for native PCIe hotplug - * either so prevent that as well. + * either so prevent that as well. However Thunderbolt controllers + * on Macs are capable of side-band signaling plug events while + * powered down, so allow them to suspend. */ - if (!dev->is_hotplug_bridge) { + if (!dev->is_hotplug_bridge || + (dev->is_thunderbolt && dmi_match(DMI_SYS_VENDOR, "Apple Inc."))) { /* * Keep the port resumed 10ms to make sure things like * config space accesses from userspace (lspci) will not @@ -243,7 +246,8 @@ static int pcie_portdrv_probe(struct pci_dev *dev, static void pcie_portdrv_remove(struct pci_dev *dev) { - if (!dev->is_hotplug_bridge) { + if (!dev->is_hotplug_bridge || + (dev->is_thunderbolt && dmi_match(DMI_SYS_VENDOR, "Apple Inc."))) { pm_runtime_forbid(&dev->dev); pm_runtime_get_noresume(&dev->dev); pm_runtime_dont_use_autosuspend(&dev->dev);
Thunderbolt controllers have a pin to signal plug events while the controller is powered down. On Macs this pin is wired to the southbridge and causes a GPE to be fired. The OS may then power up the controller to probe the newly connected device. It is thus okay to let Thunderbolt hotplug ports go to D3 on Macs. Signed-off-by: Lukas Wunner <lukas@wunner.de> --- drivers/pci/pcie/portdrv_pci.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)