diff options
| author | Mika Westerberg <mika.westerberg@linux.intel.com> | 2018-07-25 11:48:39 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-25 11:55:29 +0300 |
| commit | 2d8ff0b586fb1c5bd81a3ab286dcc6bbc432044e (patch) | |
| tree | 0bdc18fec7a9d72e29b0b754a24b9a1df876b34b /drivers/thunderbolt/xdomain.c | |
| parent | fa3af1cb1ec073265c9c87ec44faf006f2f12d96 (diff) | |
| download | linux-2d8ff0b586fb1c5bd81a3ab286dcc6bbc432044e.tar.xz | |
thunderbolt: Add support for runtime PM
When Thunderbolt host controller is set to RTD3 mode (Runtime D3) it is
present all the time. Because of this it is important to runtime suspend
the controller whenever possible. In case of ICM we have following rules
which all needs to be true before the host controller can be put to D3:
- The controller firmware reports to support RTD3
- All the connected devices announce support for RTD3
- There is no active XDomain connection
Implement this using standard Linux runtime PM APIs so that when all the
children devices are runtime suspended, the Thunderbolt host controller
PCI device is runtime suspended as well. The ICM firmware then starts
powering down power domains towards RTD3 but it can prevent this if it
detects that there is an active Display Port stream (this is not visible
to the software, though).
The Thunderbolt host controller will be runtime resumed either when
there is a remote wake event (device is connected or disconnected), or
when there is access from userspace that requires hardware access.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/thunderbolt/xdomain.c')
| -rw-r--r-- | drivers/thunderbolt/xdomain.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c index 8abb4e843085..db8bece63327 100644 --- a/drivers/thunderbolt/xdomain.c +++ b/drivers/thunderbolt/xdomain.c @@ -13,6 +13,7 @@ #include <linux/device.h> #include <linux/kmod.h> #include <linux/module.h> +#include <linux/pm_runtime.h> #include <linux/utsname.h> #include <linux/uuid.h> #include <linux/workqueue.h> @@ -1129,6 +1130,14 @@ struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent, xd->dev.groups = xdomain_attr_groups; dev_set_name(&xd->dev, "%u-%llx", tb->index, route); + /* + * This keeps the DMA powered on as long as we have active + * connection to another host. + */ + pm_runtime_set_active(&xd->dev); + pm_runtime_get_noresume(&xd->dev); + pm_runtime_enable(&xd->dev); + return xd; err_free_local_uuid: @@ -1174,6 +1183,15 @@ void tb_xdomain_remove(struct tb_xdomain *xd) device_for_each_child_reverse(&xd->dev, xd, unregister_service); + /* + * Undo runtime PM here explicitly because it is possible that + * the XDomain was never added to the bus and thus device_del() + * is not called for it (device_del() would handle this otherwise). + */ + pm_runtime_disable(&xd->dev); + pm_runtime_put_noidle(&xd->dev); + pm_runtime_set_suspended(&xd->dev); + if (!device_is_registered(&xd->dev)) put_device(&xd->dev); else |