Messages in this thread | | | Date | Thu, 16 Apr 2015 11:42:08 +0200 | From | Maxime Coquelin <> | Subject | Re: Allowing reset controllers before SMP initialization (on ARM)? |
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Hi Florian, Arnd,
On 04/16/2015 10:04 AM, Arnd Bergmann wrote: > On Wednesday 15 April 2015 17:51:18 Florian Fainelli wrote: >> Hi, >> >> In order to support initialization of the secondary core on BCM63138 >> SoCs, I would want to utilize a reset controller to release the >> secondary CPU from reset [1]. >> >> Here are multiple options: >> >> - expose a custom function which registers the reset controller platform >> driver as early as possible, which is probably acceptable, but also >> requires the DT machine descriptor to populate the platform bus earlier, >> which we could completely avoid > I think populating the platform bus earlier is not realistic, that > would break lots of existing dependencies. In particular, we can't > do it much earlier because it has to be done after the platform bus > itself is instantiated. > >> - have a OF_DECLARE_RESET_CONTROLLER() which is running fairly early >> during boot, such that we can utilize reset controllers are early as >> possible, before any initcall level, and before SMP initialization is >> kicking in > We've added a couple of those, and it could be done here, but putting > them in the right order is a bit tricky, and I think we can avoid it.
I have already proposed a OF_DECLARE_RESET_CONTROLLER() implementation: https://lkml.org/lkml/2015/2/20/395
I needed it for the STM32 timers, but it was not accepted. Now, I perform the timers reset in the bootloader, but it shouldn't work in your case.
Kind regards, Maxime
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