Messages in this thread | | | From | Linus Walleij <> | Date | Fri, 3 Aug 2018 19:24:56 +0200 | Subject | Re: [PATCH v1 1/2] pinctrl: tegra: Move drivers registration to arch_init level |
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On Thu, Aug 2, 2018 at 1:31 PM Stefan Agner <stefan@agner.ch> wrote:
> A while back at least using those init lists were not well received even > for GPIO/pinctrl drivers: > > https://lore.kernel.org/lkml/CACRpkdYk0zW12qNXgOstTLmdVDYacu0Un+8quTN+J_azOic7AA@mail.gmail.com/T/#mf0596982324a6489b5537b0531ac5aed60a316ba
You shouldn't listen too much to that guy he's not trustworthy.
> I still think we should make an exception for GPIO/pinctrl and use > earlier initcalls. Platform GPIO/pinctrl drivers provide basic > infrastructure often used by many other drivers, we want to have them > loaded early. It avoids unnecessary EPROBE_DEFER and hence probably even > boots faster.
When we have the pin control and GPIO at different initlevels it makes me uneasy because I feel we have implicit init dependencies that seem more than a little fragile.
My recent thinking has involved the component method used in DRM drivers such as drivers/gpu/drm/vc4/vc4_drv.c where a few different component subdrivers are linked together at bind time (not probe time!) into a master component.
Rob was no big fan of this but the DRM people like it and I was thinking to make a try at it.
This way we could at least probe and bind the pin control and GPIO drivers at the *same* initlevel and express the dependencies between them somewhat.
> This should definitely go in, at least as a stop gap solution.
Agreed. (And patch applied.)
Yours, Linus Walleij
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