Please ignore the e-mail. I found a way to hot remove ACPI0004 device. If I found anything related to force_remove sysfs, I'll let you know. Thanks, Yasuaki Ishimatsu On 06/28/2017 02:16 PM, YASUAKI ISHIMATSU wrote: > Our sever supports system board (defined as ACPI0004) hotplug. And to hot-remove the device safely, > we control force_remove sysfs. But due to the following commit, ACPI0004 hotplug does not work. > > commit ffc10d82ff5df7087a9b737de55a69ac4f89bf56 > Author: Michal Hocko <mhocko@xxxxxxxx> > Date: Mon Apr 3 09:40:23 2017 +0200 > > ACPI / scan: Drop support for force_remove > > ACPI0004 is defined as module device in ACPI specification. So we don't know what devices mounts on ACPI0004. > So to hot-remove ACPI0004 safely, we implemented that ACPI004 can be hot removed only when acpi_force_hot_remove > is set to 1 via force_remove sysfs. And if acpi_force_hot_remove is set to 0, kernel just notifies REMOVE request > of ACPI0004 to udev so that user can offline the devices on ACPI0004 by udev rule. > > In our udev script, we hot-removes ACPI0004 safely as follows: > > 1. udev catches REMOVE request of a ACPI0004 and run our script > 2. Our script offline all devices on the ACPI0004 > 3. Our script write 1 to force_remove sysfs so that ACPI0004 can be hot-removed. > 4. Our script write 1 to eject sysfs of the ACPI0004 to hot remove ACPI0004 > 5. Our script write 0 to force_remove sysfs so that the ACPI0004 cannot be hot-removed. > > But due to the commit ffc10d82ff5d, there is no way to hot remove ACPI0004. > So please revert the commit. > > Thanks, > Yasuaki Ishimatsu > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
