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Diffstat (limited to 'udev-config/doc/05-udev-early.txt')
| -rw-r--r-- | udev-config/doc/05-udev-early.txt | 33 |
1 files changed, 0 insertions, 33 deletions
diff --git a/udev-config/doc/05-udev-early.txt b/udev-config/doc/05-udev-early.txt deleted file mode 100644 index 9c0fb4fb8..000000000 --- a/udev-config/doc/05-udev-early.txt +++ /dev/null @@ -1,33 +0,0 @@ -Purpose of rules file: - -The kernel does not always fully populate a given kobject's attributes before -sending the uevent for that kobject. This means that a given sysfs directory -may not have all the required files in it (each directory corresponds to a -kobject, and each file corresponds to an attribute). - -Therefore, we must sometimes wait for attributes to show up when devices are -discovered. This is accomplished by udev's WAIT_FOR_SYSFS rule types. - - -Description of rules: - -All rules in this file match ACTION="add", because none of them apply when -devices are being removed. - -SUBSYSTEM is the kernel subsystem that the device uses. Current kernels have -some issues with SCSI device attributes being created too late. For any device -with a SUBSYSTEM of scsi, we must wait for the ioerr_cnt attribute. (This is -the last attribute created for SCSI devices, so when this attribute appears, -the kobject is fully populated.) - -It is also possible to use SUBSYSTEMS in Udev rules. Using SUBSYSTEMS would -cause Udev to search up the device tree for a matching SUBSYSTEM value. (Note -that "the device tree" is not necessarily the same as the path under /sys (the -DEVPATH). Rather, "up the device tree" is the path followed by udevinfo when -it is given the argument "-a".) - -We do not use SUBSYSTEMS in this rule, because we only care about the SUBSYSTEM -of the kobject in question. We don't care about devices that are children of -SCSI devices, only the SCSI device itself. We will use SUBSYSTEMS in later -rules, though. - |