[PATCH] root hub updates (greater half)
This patch associates hub suspend and resume logic (including for root hubs)
with CONFIG_PM -- instead of CONFIG_USB_SUSPEND as before -- thereby unifying
two troublesome versions of suspend logic into just one. It'll be easier to
keep things right from now on.
- Now usbcore _always_ calls hcd->hub_suspend as needed, instead of
only when USB_SUSPEND is enabled:
* Those root hub methods are now called from hub suspend/resume;
no more skipping between layers during device suspend/resume;
* It now handles cases allowed by sysfs or autosuspended root hubs,
by forcing the hub interface to resume too.
- All devices, including virtual root hubs, now get the same treatment
on their resume paths ... including re-activating all their interfaces.
Plus it gets rid of those stub copies of usb_{suspend,resume}_device(), and
updates the Kconfig to match the new definition of USB_SUSPEND: it provides
(a) selective suspend, downstream from hubs; and (b) remote wakeup, upstream
from any device configuration which supports it.
This calls for minor followup patches for most HCDs (and their PCI glue).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/Kconfig | 11 ++-
drivers/usb/core/hub.c | 163 +++++++++++++++++++++++++----------------------
2 files changed, 97 insertions(+), 77 deletions(-)
diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index 1a9ff61..ff03184 100644
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -61,14 +61,17 @@
If you are unsure about this, say N here.
config USB_SUSPEND
- bool "USB suspend/resume (EXPERIMENTAL)"
+ bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)"
depends on USB && PM && EXPERIMENTAL
help
If you say Y here, you can use driver calls or the sysfs
"power/state" file to suspend or resume individual USB
- peripherals. There are many related features, such as
- remote wakeup and driver-specific suspend processing, that
- may not yet work as expected.
+ peripherals.
+
+ Also, USB "remote wakeup" signaling is supported, whereby some
+ USB devices (like keyboards and network adapters) can wake up
+ their parent hub. That wakeup cascades up the USB tree, and
+ could wake the system from states like suspend-to-RAM.
If you are unsure about this, say N here.