| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 1 | What: /sys/class/devlink/.../ |
| 2 | Date: May 2020 |
| 3 | Contact: Saravana Kannan <saravanak@google.com> |
| 4 | Description: |
| 5 | Provide a place in sysfs for the device link objects in the |
| 6 | kernel at any given time. The name of a device link directory, |
| 7 | denoted as ... above, is of the form <supplier>--<consumer> |
| 8 | where <supplier> is the supplier bus:device name and <consumer> |
| 9 | is the consumer bus:device name. |
| 10 | |
| 11 | What: /sys/class/devlink/.../auto_remove_on |
| 12 | Date: May 2020 |
| 13 | Contact: Saravana Kannan <saravanak@google.com> |
| 14 | Description: |
| 15 | This file indicates if the device link will ever be |
| 16 | automatically removed by the driver core when the consumer and |
| 17 | supplier devices themselves are still present. |
| 18 | |
| 19 | This will be one of the following strings: |
| 20 | |
| 21 | - 'consumer unbind' |
| 22 | - 'supplier unbind' |
| 23 | - 'never' |
| 24 | |
| 25 | 'consumer unbind' means the device link will be removed when |
| 26 | the consumer's driver is unbound from the consumer device. |
| 27 | |
| 28 | 'supplier unbind' means the device link will be removed when |
| 29 | the supplier's driver is unbound from the supplier device. |
| 30 | |
| 31 | 'never' means the device link will not be automatically removed |
| 32 | when as long as the supplier and consumer devices themselves |
| 33 | are still present. |
| 34 | |
| 35 | What: /sys/class/devlink/.../consumer |
| 36 | Date: May 2020 |
| 37 | Contact: Saravana Kannan <saravanak@google.com> |
| 38 | Description: |
| 39 | This file is a symlink to the consumer device's sysfs directory. |
| 40 | |
| 41 | What: /sys/class/devlink/.../runtime_pm |
| 42 | Date: May 2020 |
| 43 | Contact: Saravana Kannan <saravanak@google.com> |
| 44 | Description: |
| 45 | This file indicates if the device link has any impact on the |
| 46 | runtime power management behavior of the consumer and supplier |
| 47 | devices. For example: Making sure the supplier doesn't enter |
| 48 | runtime suspend while the consumer is active. |
| 49 | |
| 50 | This will be one of the following strings: |
| 51 | |
| 52 | === ======================================== |
| 53 | '0' Does not affect runtime power management |
| 54 | '1' Affects runtime power management |
| 55 | === ======================================== |
| 56 | |
| 57 | What: /sys/class/devlink/.../status |
| 58 | Date: May 2020 |
| 59 | Contact: Saravana Kannan <saravanak@google.com> |
| 60 | Description: |
| 61 | This file indicates the status of the device link. The status |
| 62 | of a device link is affected by whether the supplier and |
| 63 | consumer devices have been bound to their corresponding |
| 64 | drivers. The status of a device link also affects the binding |
| 65 | and unbinding of the supplier and consumer devices with their |
| 66 | drivers and also affects whether the software state of the |
| 67 | supplier device is synced with the hardware state of the |
| 68 | supplier device after boot up. |
| 69 | See also: sysfs-devices-state_synced. |
| 70 | |
| 71 | This will be one of the following strings: |
| 72 | |
| 73 | - 'not tracked' |
| 74 | - 'dormant' |
| 75 | - 'available' |
| 76 | - 'consumer probing' |
| 77 | - 'active' |
| 78 | - 'supplier unbinding' |
| 79 | - 'unknown' |
| 80 | |
| 81 | 'not tracked' means this device link does not track the status |
| 82 | and has no impact on the binding, unbinding and syncing the |
| 83 | hardware and software device state. |
| 84 | |
| 85 | 'dormant' means the supplier and the consumer devices have not |
| 86 | bound to their driver. |
| 87 | |
| 88 | 'available' means the supplier has bound to its driver and is |
| 89 | available to supply resources to the consumer device. |
| 90 | |
| 91 | 'consumer probing' means the consumer device is currently |
| 92 | trying to bind to its driver. |
| 93 | |
| 94 | 'active' means the supplier and consumer devices have both |
| 95 | bound successfully to their drivers. |
| 96 | |
| 97 | 'supplier unbinding' means the supplier devices is currently in |
| 98 | the process of unbinding from its driver. |
| 99 | |
| 100 | 'unknown' means the state of the device link is not any of the |
| 101 | above. If this is ever the value, there's a bug in the kernel. |
| 102 | |
| 103 | What: /sys/class/devlink/.../supplier |
| 104 | Date: May 2020 |
| 105 | Contact: Saravana Kannan <saravanak@google.com> |
| 106 | Description: |
| 107 | This file is a symlink to the supplier device's sysfs directory. |
| 108 | |
| 109 | What: /sys/class/devlink/.../sync_state_only |
| 110 | Date: May 2020 |
| 111 | Contact: Saravana Kannan <saravanak@google.com> |
| 112 | Description: |
| 113 | This file indicates if the device link is limited to only |
| 114 | affecting the syncing of the hardware and software state of the |
| 115 | supplier device. |
| 116 | |
| 117 | This will be one of the following strings: |
| 118 | |
| 119 | === ================================ |
| 120 | '0' |
| 121 | '1' Affects runtime power management |
| 122 | === ================================ |
| 123 | |
| 124 | '0' means the device link can affect other device behaviors |
| 125 | like binding/unbinding, suspend/resume, runtime power |
| 126 | management, etc. |
| 127 | |
| 128 | '1' means the device link will only affect the syncing of |
| 129 | hardware and software state of the supplier device after boot |
| 130 | up and doesn't not affect other behaviors of the devices. |