Magnus Damm <magnus.damm@xxxxxxxxx> writes: > On Sun, Jul 25, 2010 at 5:24 AM, Grant Likely <grant.likely@xxxxxxxxxxxx> wrote: >> "Magnus Damm" <magnus.damm@xxxxxxxxx> wrote: >>>On Tue, Oct 27, 2009 at 8:13 AM, Kevin Hilman >>><khilman@xxxxxxxxxxxxxxxxxxx> wrote: >>>> Eric Miao <eric.y.miao@xxxxxxxxx> writes: >>>>> On Thu, Sep 24, 2009 at 7:28 AM, Kevin Hilman >>>>> <khilman@xxxxxxxxxxxxxxxxxxx> wrote: >>>>>> Mikael Pettersson wrote: >>>>>>> Eric Miao writes: >>>>>>> > On Wed, Sep 23, 2009 at 9:50 AM, Kevin Hilman >>>>>>> > <khilman@xxxxxxxxxxxxxxxxxxx> wrote: >>>>>>> > > On ARM platforms, power management can be very platform specific. >>>>>>> > > This patch allows ARM subarches to extend the platform_device >>>>>>> > > pdev_archdata for each subarch by creating a new struct pdev_machdata >>>>>>> > > and allowing each subarch to customize it as needed. > >>>Do you remember what happened with this patch? >> >> I don't have all the details in front of me because I'm on my phone, >> but I advised against pdev_archdata because it is >> multiplatform-unfriendly. > > Ok, I did not expect that. =) But after thinking a bit it does make > sense. I wonder what my options are. I'm not so fond of the idea to > wrap the platform devices - that's not more multi-platform friendly, > is it? [sorry for the lag, been on vacation] Wrapping is more multi-platform friendly because only platform-specific code accesses the wrapped code. It's also logically consistent as a struct device is contained by a platform_device which is then contained by an omap_device (in our case.) Only OMAP-specific code ever knows about or touches that layer. > How about using devres and platform bus notifiers? That seems fine too, and probably better if the amount of data/code you need is small. In the OMAP case, it's rather complicated so it's cleaner IMHO to keep it in a separate omap_device layer and struct. > For a Runtime PM prototype using devres (instead of pdev_archdata or > wrapping) look here: > https://patchwork.kernel.org/patch/113605/ > > To make it work with modules I propose adding a driver bind event: > https://patchwork.kernel.org/patch/113865/ > > Looks pretty multi-platform friendly to me. Any suggestions? Your patches look multi-platform friendly, but there are still some outstanding issues with making runtime PM support multi-platform friendly that are not direclty related to the above patches. 1) weak symbols We need to change the overriding of weak symbols into some form of register/unregister so multiple platforms in the same kernel could work. That's the easy one. 2) custom vs. platform bus. The other issue under discussion between Grant & myself[1] has been the use of a custom bus instead of the platform bus. Following your lead, (and preferring that option) I continued to use the platform_bus since I only need to override a few of the dev_pm_ops functions. However, Grant is not happy about overriding the platform_bus. He would rather see each platform create a custom bus with it's own PM methods. In this thread[1], I did a quick and dirty proof of concept to show that it is possible, but quite frankly, I still much prefer continuing to use the platform_bus since it is mostly identical. After I catch up on the rest of my mail, I will get back to this topic. Kevin [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2010-June/018925.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
