diff options
| author | Saravana Kannan | 2020-02-21 17:40:35 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2020-03-04 17:58:48 +0100 |
| commit | 8375e74f2bca9802a4ddf431a6d7bd2ab9950f27 (patch) | |
| tree | 791117d1257c1c187d5c6e0d087f8331c072fb00 /Documentation/admin-guide/kernel-parameters.txt | |
| parent | 1745d299af5b373abad08fa29bff0d31dc6aff21 (diff) | |
driver core: Add fw_devlink kernel commandline option
fwnode_operations.add_links allows creating device links from
information provided by firmware.
fwnode_operations.add_links is currently implemented only by
OF/devicetree code and a specific case of efi. However, there's nothing
preventing ACPI or other firmware types from implementing it.
The OF implementation is currently controlled by a kernel commandline
parameter called of_devlink.
Since this feature is generic isn't limited to OF, add a generic
fw_devlink kernel commandline parameter to control this feature across
firmware types.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200222014038.180923-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index dbc22d684627..29985152b66d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1350,6 +1350,24 @@ can be changed at run time by the max_graph_depth file in the tracefs tracing directory. default: 0 (no limit) + fw_devlink= [KNL] Create device links between consumer and supplier + devices by scanning the firmware to infer the + consumer/supplier relationships. This feature is + especially useful when drivers are loaded as modules as + it ensures proper ordering of tasks like device probing + (suppliers first, then consumers), supplier boot state + clean up (only after all consumers have probed), + suspend/resume & runtime PM (consumers first, then + suppliers). + Format: { off | permissive | on | rpm } + off -- Don't create device links from firmware info. + permissive -- Create device links from firmware info + but use it only for ordering boot state clean + up (sync_state() calls). + on -- Create device links from firmware info and use it + to enforce probe and suspend/resume ordering. + rpm -- Like "on", but also use to order runtime PM. + gamecon.map[2|3]= [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port) |