Messages in this thread | | | Date | Tue, 15 Nov 2016 07:41:24 -0800 | From | Tony Lindgren <> | Subject | Re: [PATCH 1/5] pinctrl: core: Use delayed work for hogs |
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* Linus Walleij <linus.walleij@linaro.org> [161114 22:53]: > On Tue, Nov 15, 2016 at 1:47 AM, Tony Lindgren <tony@atomide.com> wrote: > > > 8< -------------------------------- > > From tony Mon Sep 17 00:00:00 2001 > > From: Tony Lindgren <tony@atomide.com> > > Date: Tue, 25 Oct 2016 08:33:35 -0700 > > Subject: [PATCH] pinctrl: core: Use delayed work for hogs > > > > Having the pin control framework call pin controller functions > > before it's probe has finished is not nice as the pin controller > > device driver does not yet have struct pinctrl_dev handle. > > > > Let's fix this issue by adding deferred work for late init. This is > > needed to be able to add pinctrl generic helper functions that expect > > to know struct pinctrl_dev handle. Note that we now need to call > > create_pinctrl() directly as we don't want to add the pin controller > > to the list of controllers until the hogs are claimed. We also need > > to pass the pinctrl_dev to the device tree parser functions as they > > otherwise won't find the right controller at this point. > > > > Signed-off-by: Tony Lindgren <tony@atomide.com> > > This looks a lot better! > > So if I understand correctly, we can guarantee that the delayed > work will not execute until the device driver probe() has finished, > and it *will* execute immediately after that? > > So: > - Device driver probes > - Delayed work is called > - Next initcall > > I'm not 100% familiar with how delayed work works... :/
Yeah well the delayed work gets scheduled for next jiffy but may be pre-empted as it runs in process context.
So in the worst case it could that we still may need to fix few drivers to support -EPROBE_DEFER. I wonder if we should check for hogs in probe already and only defer if hogs are defined?
Regards,
Tony
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