Messages in this thread | | | Date | Thu, 25 Jan 2018 16:31:25 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH V6 Resend 00/13] drivers: Boot Constraint core |
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On 10-01-18, 17:13, Rob Herring wrote: > On Tue, Jan 9, 2018 at 9:47 PM, Viresh Kumar <viresh.kumar@linaro.org> wrote: > > A typical example of that can be the LCD controller, which is used by > > the bootloaders to show image(s) while the platform is booting into > > Linux. The LCD controller can be using some resources, like clk, > > regulators, etc, that are shared between several devices. These shared > > resources should be configured to satisfy need of all the users. If > > another device's (X) driver gets probed before the LCD controller driver > > in this case, then it may end up disabling or reconfiguring these > > resources to ranges satisfying the current users (only device X) and > > that can make the LCD screen unstable. > > We already have simple fb and a binding for it. It only handles clocks > I think, but could be extended to other things. I rather not extend > it, but it is there already and we don't need different solutions for > this.
Got a bit busy lately and wasn't able to look into the details of it.
So AFAICT the basic problem I was trying to solve still exists with simple-fb as well. And the problem is that nothing prevents another driver to get probed before the display driver (or simple-fb) and reconfigure the resources. Even if we let simple-fb come up really early, the resources like clk/regulator may not be available. And so the ordering thing is still unsolved for me.
-- viresh
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