Re: [PATCHv3 0/4] drivers/base: bugfix for supplier<-consumer ordering in device_kset

On Mon, Jul 9, 2018 at 10:40 AM, Pingfan Liu [off-list ref] wrote:

On Mon, Jul 9, 2018 at 3:48 PM Rafael J. Wysocki [off-list ref] wrote:

quoted

On Mon, Jul 9, 2018 at 8:48 AM, Pingfan Liu [off-list ref] wrote:

quoted

On Sun, Jul 8, 2018 at 4:25 PM Rafael J. Wysocki [off-list ref] wrote:

[cut]

quoted

I simply think that there should be one way to iterate over devices
for both system-wide PM and shutdown.

The reason why it is not like that today is because of the development
history, but if it doesn't work and we want to fix it, let's just
consolidate all of that.

Now, system-wide suspend resume sometimes iterates the list in the
reverse order which would be hard without having a list, wouldn't it?

Yes, it would be hard without having a list. I just thought to use
device tree info to build up a shadowed list, and rebuild the list
until there is new device_link_add() operation. For
device_add/_remove(), it can modify the shadowed list directly.

Right, and that's the idea of dpm_list, generally speaking: It
represents one of the (possibly many) orders in which devices can be
suspended (or shut down) based on the information coming from the
device hierarchy and device links.

So it appears straightforward (even though it may be complicated
because of the build-time dependencies) to start using dpm_list for
shutdown too - and to ensure that it is properly maintained
everywhere.

Thanks,
Rafael