Greg,
Here is the port power control rework for your consideration now that
Alan has finished acking it (see summary below). Patch 9 had one
outstanding minor question from Alan that I believe I have addressed.
Patch 16 has a checkpatch warning "WARNING: msleep < 20ms can sleep for
up to 20ms", but it's flagging old code that simply moved and a 20ms
timeout is acceptable.
Changes since v9 [1]:
* Reworked the forced wakeup mechanism in patch 17 to use
pm_request_resume()
* Random collection of fixlets and rewordings suggested by Alan.
=====
This series addresses the following disconnect scenarios when attempting
to use port power-off.
1/ Superspeed devices downgrade to their hispeed connection when
rx-detection fails on the superspeed pins. Address this by
preventing superspeed port poweroff/suspension until the peer port is
suspended, and powering on the superspeed port before the hispeed
port is resumed. This depends on the ability to identify peer ports
(patches 5-8, and patch 10 implements the policy).
2/ khubd prematurely disconnects ports that are in the process of being
resumed or reset. After this series khubd will ignore ports in the
pm-runtime-suspended or suspending state, or force active ports in the
resuming state (patch 14). While it is running it holds a new port
status lock to synchronize the port status changes of
usb_port_{suspend|resume} and usb_reset_and_verify_device() (patch 15).
3/ Superspeed devices fail to reconnect after a 2 second timeout This
event has two causes:
3.1/ Repeated {Set|Clear}PortFeature(PORT_POWER) toggles results in
the the device switching to its hispeed connection (due to
perceived instability of the superspeed connection). Address
this by arranging for the child device to be woken up
and complete a resume cycle when the parent port resumes (patch 17).
3.2/ Devices may require a warm reset when recovering the power
session. When the child device is woken up per above and the
port timed out on reconnect, force a warm-reset during the
child's reset-resume (patch 18).
[1]: v9: http://marc.info/?l=linux-usb&m=139952735227163&w=2
---
ACK => Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
ack => Acked-by another reviewer
ACK [01/19] USB: mutual exclusion for resetting a hub and power-managing a port
ACK [02/19] usb: disable port power control if not supported in wHubCharacteristics
ACK [03/19] usb: rename usb_port device objects
ACK [04/19] usb: cleanup setting udev->removable from port_dev->connect_type
ACK [05/19] usb: assign default peer ports for root hubs
ACK [06/19] usb: assign usb3 external hub port peers
ACK [07/19] usb: find internal hub tier mismatch via acpi
ACK [08/19] usb: sysfs link peer ports
[09/19] usb: make usb_port flags atomic, rename did_runtime_put to child_usage
ACK [10/19] usb: block suspension of superspeed port while hispeed peer is active
ACK [11/19] usb: don't clear FEAT_C_ENABLE on usb_port_runtime_resume failure
ACK [12/19] usb: usb3 ports do not support FEAT_C_ENABLE
ACK [13/19] usb: refactor port handling in hub_events()
ACK [14/19] usb: synchronize port poweroff and khubd
ACK [15/19] usb: introduce port status lock
ACK [16/19] usb: hub_handle_remote_wakeup() depends on CONFIG_PM_RUNTIME=y
ACK [17/19] usb: resume child device when port is powered on
ack [18/19] usb: force warm reset to break link re-connect livelock
[19/19] usb: documentation for usb port power off mechanisms
Alan Stern (1):
USB: mutual exclusion for resetting a hub and power-managing a port
Dan Williams (17):
usb: disable port power control if not supported in wHubCharacteristics
usb: rename usb_port device objects
usb: cleanup setting udev->removable from port_dev->connect_type
usb: assign default peer ports for root hubs
usb: assign usb3 external hub port peers
usb: find internal hub tier mismatch via acpi
usb: sysfs link peer ports
usb: make usb_port flags atomic, rename did_runtime_put to child_usage
usb: block suspension of superspeed port while hispeed peer is active
usb: don't clear FEAT_C_ENABLE on usb_port_runtime_resume failure
usb: usb3 ports do not support FEAT_C_ENABLE
usb: refactor port handling in hub_events()
usb: synchronize port poweroff and khubd
usb: introduce port status lock
usb: hub_handle_remote_wakeup() depends on CONFIG_PM_RUNTIME=y
usb: resume child device when port is powered on
usb: force warm reset to break link re-connect livelock
Lan Tianyu (1):
usb: documentation for usb port power off mechanisms
Documentation/usb/power-management.txt | 242 ++++++++
drivers/usb/core/hcd.c | 45 +
drivers/usb/core/hub.c | 965 +++++++++++++++++---------------
drivers/usb/core/hub.h | 43 +
drivers/usb/core/port.c | 310 +++++++++-
drivers/usb/core/usb-acpi.c | 107 ++--
drivers/usb/core/usb.h | 16 -
7 files changed, 1166 insertions(+), 562 deletions(-)
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