forked from Minki/linux
e020ff611b
The device link device's name was of the form:
<supplier-dev-name>--<consumer-dev-name>
This can cause name collision as reported here [1] as device names are
not globally unique. Since device names have to be unique within the
bus/class, add the bus/class name as a prefix to the device names used to
construct the device link device name.
So the devuce link device's name will be of the form:
<supplier-bus-name>:<supplier-dev-name>--<consumer-bus-name>:<consumer-dev-name>
[1] - https://lore.kernel.org/lkml/20201229033440.32142-1-michael@walle.cc/
Fixes: 287905e68d ("driver core: Expose device link details in sysfs")
Cc: stable@vger.kernel.org
Reported-by: Michael Walle <michael@walle.cc>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210110175408.1465657-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
131 lines
4.4 KiB
Plaintext
131 lines
4.4 KiB
Plaintext
What: /sys/class/devlink/.../
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Date: May 2020
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Contact: Saravana Kannan <saravanak@google.com>
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Description:
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Provide a place in sysfs for the device link objects in the
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kernel at any given time. The name of a device link directory,
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denoted as ... above, is of the form <supplier>--<consumer>
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where <supplier> is the supplier bus:device name and <consumer>
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is the consumer bus:device name.
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What: /sys/class/devlink/.../auto_remove_on
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Date: May 2020
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Contact: Saravana Kannan <saravanak@google.com>
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Description:
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This file indicates if the device link will ever be
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automatically removed by the driver core when the consumer and
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supplier devices themselves are still present.
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This will be one of the following strings:
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- 'consumer unbind'
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- 'supplier unbind'
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- 'never'
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'consumer unbind' means the device link will be removed when
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the consumer's driver is unbound from the consumer device.
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'supplier unbind' means the device link will be removed when
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the supplier's driver is unbound from the supplier device.
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'never' means the device link will not be automatically removed
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when as long as the supplier and consumer devices themselves
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are still present.
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What: /sys/class/devlink/.../consumer
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Date: May 2020
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Contact: Saravana Kannan <saravanak@google.com>
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Description:
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This file is a symlink to the consumer device's sysfs directory.
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What: /sys/class/devlink/.../runtime_pm
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Date: May 2020
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Contact: Saravana Kannan <saravanak@google.com>
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Description:
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This file indicates if the device link has any impact on the
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runtime power management behavior of the consumer and supplier
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devices. For example: Making sure the supplier doesn't enter
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runtime suspend while the consumer is active.
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This will be one of the following strings:
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=== ========================================
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'0' Does not affect runtime power management
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'1' Affects runtime power management
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=== ========================================
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What: /sys/class/devlink/.../status
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Date: May 2020
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Contact: Saravana Kannan <saravanak@google.com>
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Description:
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This file indicates the status of the device link. The status
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of a device link is affected by whether the supplier and
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consumer devices have been bound to their corresponding
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drivers. The status of a device link also affects the binding
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and unbinding of the supplier and consumer devices with their
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drivers and also affects whether the software state of the
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supplier device is synced with the hardware state of the
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supplier device after boot up.
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See also: sysfs-devices-state_synced.
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This will be one of the following strings:
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- 'not tracked'
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- 'dormant'
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- 'available'
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- 'consumer probing'
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- 'active'
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- 'supplier unbinding'
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- 'unknown'
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'not tracked' means this device link does not track the status
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and has no impact on the binding, unbinding and syncing the
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hardware and software device state.
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'dormant' means the supplier and the consumer devices have not
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bound to their driver.
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'available' means the supplier has bound to its driver and is
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available to supply resources to the consumer device.
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'consumer probing' means the consumer device is currently
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trying to bind to its driver.
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'active' means the supplier and consumer devices have both
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bound successfully to their drivers.
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'supplier unbinding' means the supplier devices is currently in
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the process of unbinding from its driver.
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'unknown' means the state of the device link is not any of the
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above. If this is ever the value, there's a bug in the kernel.
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What: /sys/class/devlink/.../supplier
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Date: May 2020
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Contact: Saravana Kannan <saravanak@google.com>
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Description:
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This file is a symlink to the supplier device's sysfs directory.
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What: /sys/class/devlink/.../sync_state_only
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Date: May 2020
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Contact: Saravana Kannan <saravanak@google.com>
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Description:
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This file indicates if the device link is limited to only
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affecting the syncing of the hardware and software state of the
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supplier device.
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This will be one of the following strings:
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=== ================================
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'0'
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'1' Affects runtime power management
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=== ================================
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'0' means the device link can affect other device behaviors
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like binding/unbinding, suspend/resume, runtime power
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management, etc.
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'1' means the device link will only affect the syncing of
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hardware and software state of the supplier device after boot
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up and doesn't not affect other behaviors of the devices.
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